Description:FIELD OF THE INVENTION
[001] The present invention relates to a control unit assembly for a vehicle and a method of assembling the control unit assembly.

BACKGROUND OF THE INVENTION
[002] In recent past, vehicles are embedded with electronic components for precise control over electrical systems and/or subsystems in the vehicle. One such electronic component provided in the vehicle is a Vehicle Control Unit (VCU) or a Vehicle Electronic Control Unit (VECU). The VCU is adapted to monitor and control the electrical systems and/or the subsystems of the vehicle. In addition to VCU, separate control units are also be provided in the vehicle based on the electrical component to be monitored and controlled. As an example, for an electric vehicle a motor control unit is provided for monitoring and controlling operation of an electric motor. These, control units or control unit modules are assembled in the electric vehicle for monitoring the electrical components in the vehicle.
[003] However, the separate control units necessitate additional space in the vehicle for mounting or packaging. As such, the separate control units create a space constraint in the vehicle with regards to packaging, consequently making the design cumbersome and costly. Moreover, separate control units also necessitate extra wiring harness in the vehicle, making the design of the vehicle further cumbersome and expensive. Also, additional wiring harness may bring about voltage drop and thermal issues between control units, which is undesirable.
[004] In view of the above, there is a need for a control unit assembly for a vehicle and a method of assembling thereof, which addresses one or more limitations stated above.

SUMMARY OF THE INVENTION
[005] In one aspect, a control unit assembly for a vehicle is disclosed. The control unit assembly comprising a first Printed Circuit Board (PCB) comprising an upper surface and a lower surface, wherein the upper surface is provided with one or more power control components. A second PCB comprising a bottom surface and a top surface is provided, wherein the bottom surface is provided with one or more motor-control components, wherein the bottom surface of the second PCB is mounted onto the upper surface of the first PCB. A third PCB comprising a first surface and a second surface is also provided. The first surface is provided with one or more vehicle function control components and an electrical socket, wherein the second surface of the third PCB being mounted onto the top surface of the second PCB. A heat exchanging device is mounted onto the lower surface of the first PCB and adapted to be in thermal contact with the one or more motor-control components provided on the bottom surface of the second PCB. The heat exchanging device is configured to dissipate heat generated within the control unit assembly.
[006] In an embodiment, a casing is adapted to enclose each of the first PCB, the second PCB and the third PCB, wherein the casing is mounted onto the heat exchanging device.
[007] In an embodiment, the heat exchanging device comprises an upper surface provided with plurality of cylindrical fin members.
[008] In an embodiment, the second PCB and the third PCB comprising one or more slots. Each of the one or more slots is adapted to receive a fastener, wherein each fastener is configured to engage with a nut member provided on the upper surface of the first PCB for facilitating assembly of the first PCB, the second PCB and the third PCB.
[009] In an embodiment, dimensions of the first PCB are smaller than the dimensions of the second PCB for facilitating thermal contact between the one or more motor-control components provided on the bottom surface of the second PCB and the heat exchanging device.
[010] In an embodiment, the heat exchanging device is a heat sink device.
[011] In an embodiment, the motor-control components provided on the bottom surface of the second PCB are capacitors.
[012] In another aspect, a method of assembling a control unit assembly is provided. The method comprises disposing, the first PCB in a casing, the first PCB having an upper surface provided with power control components and a lower surface. The second PCB is then mounted on the first PCB, the second PCB having a bottom surface and a top surface comprising motor-control components, wherein the bottom surface of the second PCB is mounted onto the upper surface of the first PCB. The third PCB is thereafter mounted on the second PCB, the third PCB comprising a first surface having vehicle function control components and a second surface, wherein the second surface of the third PCB is mounted onto the top surface of the second PCB. Subsequently, the heat exchanging device is mounted onto the lower surface of the first PCB, the heat exchanging device being adapted to thermally contact the motor-control components provided on the bottom surface of the second PCB, wherein the heat exchanging device comprises a lower surface provided with a plurality of grooves, the plurality of grooves being adapted to receive the motor-control components provided on the bottom surface of the second PCB for ensuring thermal contact. The heat exchanging device is configured to dissipate heat generated within the control unit assembly.

BRIEF DESCRIPTION OF THE DRAWINGS
[013] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 is a schematic view of a control unit assembly for a vehicle, in accordance with an embodiment of the present invention.
Figure 2 is an exploded view of the control unit assembly, in accordance with an embodiment of the present invention.
Figure 3 is a flow diagram of a method of assembling the control unit assembly, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[014] Various features and embodiments of the present invention here will be discernible from the following further description thereof, set out hereunder. In the ensuing exemplary embodiments, the vehicle can be a multi-wheeled vehicle.
[015] The present invention relates to a control unit assembly for a vehicle and a method of assembling the control unit assembly.
[016] Figure 1 illustrates a schematic view of a control unit assembly 100, in accordance with an exemplary embodiment of the present disclosure. The control unit assembly 100 is configured to accommodate multiple control units of the vehicle (not shown), mitigating packaging constraints in the vehicle.
[017] Referring to Figure 2 in conjunction with Figure 1, the control unit assembly 100 comprises a first Printed Circuit Board (PCB) 102 comprising an upper surface 102a and a lower surface 102b. The upper surface 102a is provided with one or more power control components 104. As such, the first PCB 102 acts as a power board or a power control board of the control unit assembly 100. In an embodiment, the one or more power control components 104 may comprise surge arrestors, circuit breakers, terminal blocks, transformers and the like. The one or more power control components 104 are located strategically on the upper surface 102a. Also, configuration of the one or more power control components are selected according to the power requirements of electrical components (not shown) in the vehicle.
[018] Further, a second PCB 106 comprising a bottom surface 106b and a top surface 106a is provided on the first PCB 102, such that the bottom surface 106b of the second PCB 106 is mounted onto the upper surface 102a of the first PCB 102. The bottom surface 106b is provided with one or more motor-control components 108a, 108b. As such, the second PCB 106 acts as a motor control board of the control unit assembly 100. In an embodiment, the one or more motor control components 108a, 108b may comprise motor control accessories, motor circuit breakers, motor starters, capacitors and the like. The one or more motor control components 108a, 108b are located on the second PCB 106 such that, motor control components 108a are mounted on the top surface 106a, while the motor control components 108b are mounted on the bottom surface 106b of the second PCB 106. In an embodiment, the motor control components 108a comprises motor control accessories, motor circuit breakers, motor starters, while the motor control components 108b comprises capacitors which are mounted on the bottom surface 106b of the second PCB 106. In the present embodiment, the motor control components 108a, 108b are provided strategically on the top surface 106a and the bottom surface 106b of the second PCB 106. Also, configuration of the one or more motor control components 108a, 108b are considered according to power requirements and operation of an electric motor (not shown) of the vehicle.
[019] Additionally, the control unit assembly 100 comprises a third PCB 110 mounted on the second PCB 106. The third PCB 110 comprises a first surface 110a and a second surface 110b. The first surface 110a is provided with one or more vehicle function control components 128 and an electrical socket 112, while the second surface 110b is mounted onto the top surface 106a of the second PCB 106. As such, the third PCB 110 acts as a vehicle function control board. The electrical socket 112 is adapted to be connectable to a wiring harness (not shown) for receiving power from a battery module (not shown) of the vehicle or for electrically coupling with electrical components of the vehicle. In an embodiment, the first surface 110a is a top surface of the third PCB 110, while the second surface 110b is a bottom surface of the third PCB 110. In an embodiment, the vehicle function control components comprise transistors, capacitors, diodes, resistors and the like.
[020] In an embodiment, each of the first PCB 102, the second PCB 106 and the third PCB 110 are mounted to one another via fastening. In the present embodiment, the second PCB 106 and the third PCB 110 comprises one or more slots 122 (shown in Figure 2). The one or more slots 122 is adapted to receive a fastener 124, The fastener 124 is configured to engage with a nut member 126 (shown in Figure 2) provided on the upper surface 102a of the first PCB 102 for facilitating assembly of the first PCB 102, the second PCB 106 and the third PCB 110.
[021] Further, the control unit assembly 100 comprises a heat exchanging device 114 mounted onto the lower surface 102b of the first PCB 102. In the present embodiment, the heat exchanging device 114 is a heat sink device. The heat exchanging device 114 is adapted to be in thermal contact with the one or more motor-control components 108b provided on the bottom surface 106b of the second PCB 106. As such, the heat exchanging device 114 is configured to dissipate the heat generated within the control unit assembly 100.
[022] The heat exchanging device 114 comprises a lower surface 114b provided with a plurality of grooves 120 which are adapted to receive the motor-control components 108b for ensuring thermal contact. The heat exchanging device 114 also comprises an upper surface 114a provided with plurality of cylindrical fin members 118. The plurality of cylindrical fin members 118 extend laterally from the upper surface 114a and are adapted to enhance the surface area of contact with ambient air, thereby increasing the rate of heat dissipation in the control unit assembly 100. In an embodiment, the upper surface 114a may include a fan member (not shown) instead of the plurality of cylindrical fin members 118 for improving the rate of heat dissipation in the control unit assembly 100.
[023] In the present embodiment, the plurality of grooves 120 are circular in shape and are located on the lower surface 114b corresponding to the location of the motor control components 108b on the second PCB 106. The plurality of grooves 120 are also configured with a depth so that the motor control components 108b are accommodated within the heat exchanging device 114. As such, the motor control components 108b (i.e. the capacitors) get inserted into the grooves 120. The motor control components 108b upon insertion (as shown in Figure 1) contact the inner surface of the groove 120, thereby establishing thermal contact. Alternatively, the motor control components 108b upon insertion into the grooves 120 contact an inner surface (not shown) of the heat exchanging device 114 for establishing thermal contact. In another embodiment, the shape and dimensions of the plurality of grooves can be selected as per design feasibility and requirement.
[024] In an embodiment, dimensions of the first PCB 102 are smaller than the dimensions of the second PCB 106. Such a constructions allows the motor control components 108b to project beyond the first PCB 102 upon mounting, thereby facilitating thermal contact between the one or more motor-control components 108b and the heat exchanging device 114. In the present embodiment, the first PCB 102 is dimensioned so as to be positioned between the motor components 108b (as shown in Figure 1) upon mounting, while also being compact.
[025] Further, the control unit assembly 100 comprises a casing 116 (shown in Figure 2) mounted onto the heat exchanging device 114. In the present embodiment, the casing 116 is adapted to engage with along periphery of the heat exchanging device 114. Upon engagement, the casing 116 may be fastened to the heat exchanging device 114. The casing 116 is adapted to enclose each of the first PCB 102, the second PCB 106 and the third PCB 110. In an embodiment, the casing 116 is also provided with slots 130 corresponding to the slots 120 provided to the second PCB 106 and the third PCB 110, so that the fastener 124 can be inserted through the casing 116 and thus mount and enclose the first PCB 102, the second PCB 106 and the third PCB 110 altogether with the casing 116. Thus, the control unit assembly 100 of the present embodiment is capable of accommodating the power control board, the motor control board and the vehicle function control board, thereby mitigating packaging constraints in the vehicle. In an embodiment, the casing 116 is made of a metallic material or a non-metallic material or a composite material. In an embodiment, the casing 116 is provided with a socket 132 for coupling with electrical component or with the battery module of the vehicle.
[026] Figure 3 is a flow diagram of a method (300) of assembling the control unit assembly 100, in accordance with an exemplary embodiment of the present disclosure.
[027] At step 302, the second PCB 106 is mounted on the first PCB 102 such that, the bottom surface 106b of the second PCB 106 engages with the upper surface 102a of the first PCB 102. Thereafter, the third PCB 110 is mounted onto the second PCB 106 at step 304 such that, the first surface 110a of the third PCB 110 engages with the top surface 106a of the second PCB 106.
[028] Subsequently, at step 306, the heat exchanging device 114 is mounted onto the lower surface of the first PCB 102. Upon mounting, the motor control components 108b which are projecting beyond the first PCB 102 gets inserted into the grooves 120 for establishing thermal contact. As each of the first PCB 102, the second PCB 106 and the third PCB 110 are mounted together, contact between the second PCB 105 and the heat exchanging device 114 establishes thermal contact with each of the first PCB 102, the second PCB 106 and the third PCB 110. Thus, the heat exchanging device 114 dissipates the heat generated in each of the first PCB 102, the second PCB 106 and the third PCB 110. In an embodiment, the heat exchanging device 114 is mounted onto the first PCB 102 via conventional mounting techniques such as fastening, brazing and the like, as per feasibility and requirement. In another embodiment, the heat exchanging device 114 is mounted onto the lower surface of the first PCB 102 upon engagement or surface contact therebetween.
[029] Thereafter, at step 308, the casing 116 is mounted onto the heat exchanging device 114 while enclosing the first PCB 102, the second PCB 106 and the third PCB 110. The casing 116 is mounted onto the heat exchanging device 114 such that, the casing 116 engages with the periphery of the lower surface 114b of the heat exchanging device 114. Upon engagement, the casing 116 may be fastened with the lower surface of the heat exchanging device 114. Upon engagement with the heat exchanging device 114, the fastener 124 is inserted through the casing 116, the second PCB 106 and the third PCB 110 for engagement with the nut member 126. Upon engagement between the fastener 124 and the nut member 126, the casing 116 encloses the first PCB 102, the second PCB 106 and the third PCB 110 to form the control unit assembly 100.
[030] The claimed invention as disclosed above is not routine, conventional or well understood in the art, as the claimed aspects enable the following solutions to the existing problems in conventional technologies. Specifically, the claimed aspect of the control unit assembly 100 including the first PCB 102, the second PCB 106 and the third PCB 110 mitigates packaging constraints in the vehicle. Also, the grooves 120 which accommodate the motor control components 108b makes the assembly compact, while also ensuring heat dissipation within the control unit assembly 100, consequently enhancing service life and durability of the control unit assembly 100. Moreover, due to the assembly of the first PCB 102, the second PCB 106 and the third PCB 110, the requirement of lengthy wiring harness is mitigated, thereby making the control unit assembly 100 compact, simple in construction and inexpensive.
Reference numerals
100 Control unit assembly
102 First PCB
102a Upper surface
102b Lower surface
104 Power control components
106 Second PCB
106a Top surface
106b Bottom surface
108 Motor control components
110 Third PCB
110a First surface
110b Second surface
112 Electrical socket
114 Heat exchanging device
114a Upper surface of heat exchanging device
114b Lower surface of heat exchanging device
116 Casing
118 Plurality of cylindrical fin members
120 Grooves
122 Slots
124 Fastener
126 Nut member
128 Vehicle function control components
130 Slots on casing
132 Socket on casing
 
, Claims:WE CLAIM:
1. A control unit assembly (100) for a vehicle, the control unit assembly (100) comprising:
a first Printed Circuit Board (PCB) (102) comprising an upper surface (102a) and a lower surface (102b), wherein the upper surface (102a) being provided with one or more power control components (104);
a second PCB (106) comprising a bottom surface (106b) and a top surface (106a), wherein the bottom surface (106b) being provided with one or more motor-control components (108a, 108b), wherein the bottom surface (106b) of the second PCB (106) being mounted onto the upper surface (102a) of the first PCB (102);
a third PCB (110) comprising a first surface (110a) and a second surface (110b), wherein the first surface (110a) being provided with one or more vehicle function control components (128) and an electrical socket (112), wherein the second surface (110b) of the third PCB (110) being mounted onto the top surface (106a) of the second PCB (106); and
a heat exchanging device (114) mounted onto the lower surface (102b) of the first PCB (102) and adapted to be in thermal contact with the one or more motor-control components (108b) provided on the bottom surface (106b) of the second PCB (106), wherein the heat exchanging device (114) comprises a lower surface (114b) provided with a plurality of grooves (120), the plurality of grooves (120) being adapted to receive the motor-control components (108b) provided on the bottom surface (106b) of the second PCB (106) for ensuring thermal contact, the heat exchanging device (114) configured to dissipate heat generated within the control unit assembly (100).

2. The control unit assembly (100) as claimed in claim 1 comprising a casing (116) adapted to enclose each of the first PCB (102), the second PCB (106) and the third PCB (110).

3. The control unit assembly (100) as claimed in claim 2, wherein the casing (116) is mounted onto the heat exchanging device (114).

4. The control unit assembly (100) as claimed in claim 1, wherein the heat exchanging device (114) comprises an upper surface (114a) provided with plurality of cylindrical fin members (118).

5. The control unit assembly (100) as claimed in claim 1, wherein the second PCB (106) and the third PCB (110) comprising one or more slots (122), each of the one or more slots (122) being adapted to receive a fastener (124), wherein each fastener (124) is configured to engage with a nut member (126) provided on the upper surface (102a) of the first PCB (102) for facilitating assembly of the first PCB (102), the second PCB (106) and the third PCB (110).

6. The control unit assembly (100) as claimed in claim 1, wherein dimensions of the first PCB (102) are smaller than the dimensions of the second PCB (106) for facilitating thermal contact between the one or more motor-control components (108a, 108b) provided on the bottom surface (106b) of the second PCB (106) and the heat exchanging device (114).

7. The control unit assembly (100) as claimed in claim 1, wherein the heat exchanging device (114) is a heat sink device.

8. The control unit assembly (100) as claimed in claim 1, wherein the motor-control components (108b) provided on the bottom surface (106b) of the second PCB (106) are capacitors.

9. A method (300) of assembly of a control unit assembly (100), the method (300) comprising:
mounting, a second PCB (106) on a first PCB (102), the second PCB (106) having a bottom surface (106b) and a top surface (106a) comprising motor-control components (108a, 108b), wherein the bottom surface (106b) of the second PCB (106) is mounted onto an upper surface (102a) of the first PCB (102);
mounting, a third PCB (110) on the second PCB (106), the third PCB (110) comprising a first surface (110a) having vehicle function control components (128) and a second surface (110b), wherein the second surface (110b) of the third PCB (110) is mounted onto the top surface (106a) of the second PCB (106);
mounting, a heat exchanging device (114) onto the lower surface (102b) of the first PCB (102), the heat exchanging device (114) adapted to thermally contact the motor-control components (108b) provided on the bottom surface (106b) of the second PCB (106), wherein the heat exchanging device (114) comprises a lower surface (114b) provided with a plurality of grooves (120), the plurality of grooves (120) being adapted to receive the motor-control components (108b) provided on the bottom surface (106b) of the second PCB (106) for ensuring thermal contact, the heat exchanging device (114) configured to dissipate heat generated within the control unit assembly (100); and
mounting, a casing (116) onto the heat exchanging device (114), wherein the casing (116) is mounted onto the heat exchanging device (114) upon enclosing the first PCB (102), the second PCB (106) and the third PCB (110).

10. The method (300) as claimed in claim 9 comprising inserting, a fastener (124) into each slot of one or more slots (122) provided on the second PCB (106) and the third PCB (110) and into each slot (130) provided on the casing (116), wherein each fastener (124) is configured to engage with a nut member (126) provided on the upper surface (102a) of the first PCB (102) for facilitating assembly of the casing (116), the first PCB (102), the second PCB (106) and the third PCB (110).

Dated this 29th day of June 2022

TVS MOTOR COMPANY LIMITED
By their Agent & Attorney

(Nikhil Ranjan)
of Khaitan & Co
Reg No IN/PA-1471