CLIAMS:We Claim;

1. A governor for inline fuel injection pump comprising;
a pair of fly weights (105a) and (105b) in communication with a cam shaft (102) of said inline fuel injection pump;
a pair of link arms (106a) and (106b) in contact with said pair of fly weights (105a) and (105b);
a connecting rod (110) in contact with said pair of link arms (106a) and (106b), said connecting rod (110) moves in response to movement of said pair of fly weights (105a) and (105b); characterized in that
a wedge (115) in contact with said connecting rod (110), said wedge (115) is adapted to move in accordance with movement of said connecting rod (110);
a beam (120) comprising a first end and a second end, said beam (120) is adapted to slide along an inclined portion of said wedge (115);
a guide element (125) comprising a guide rail (130), and said guide element (125) is in contact with said second end of said beam (120), said guide element (125) is adapted to move in vertical direction and horizontal direction; and
a connecting means (132) in contact with a control rack (135), wherein said connecting means (132) is adapted to slide along said guide rail (130) in said guide element (125), sliding of said connecting means (132) along guide rail (130) enables movement of said control rack (135) in the horizontal direction thereby enabling control of fuel injection quantity.
2. The governor as claimed in claim 1, wherein said guide element (125) moves in direction of said connecting rod (110) until a first spring is compressed to a maximum extent.

3. The governor as claimed in claim 1, wherein sliding of said beam (120) along said inclined portion of said wedge (115) is enabled using a rolling contact.

4. The governor as claimed in claim 1, wherein said guide element (125) is in contact with an accelerator pedal (160).

5. The governor as claimed in claim 4, wherein said guide element (125) moves in the horizontal direction in response to pressing and releasing of said accelerator pedal (160).

6. The governor as claimed in claim 1, wherein said guide element (125) moves in said vertical direction in response to sliding of said beam (120) along length of said wedge (115).
,TagSPECI:Field of the invention
[001] This invention relates to a governor for inline fuel injection pump.

Background of the invention
[002] Components in an inline fuel injection pump comprise a plunger and barrel assembly, delivery valve assembly, high pressure line, a control rack and a governor for controlling fuel injection quantity. Fuel injection quantity is required to be regulated depending on engine speed and driver demand provided through an accelerator pedal.

[003] Regulation of the fuel injection quantity is performed using the control rack. A governor is adapted to adjust the control rack position, which in-turn regulates the quantity of fuel injected, based on the engine speed and the driver demand.

[004] The governor comprises mechanical elements for adjusting the control rack position. Some of the mechanical elements include a guide bushing, a linkage lever, a fulcrum lever and a negative adaptation lever. These mechanical elements are connected such that the control rack position can be varied based on the engine speed and the driver demand. An Indian application number 4406/CHE/2013 discloses one such governor in detail.

Brief description of the accompanying drawings
[005] Figure 1 illustrates a governor for inline fuel injection pump, in accordance with one embodiment;

[006] Figure 2A-2D is an exemplary illustration that represents position of the connecting means on the guide rail at various engine speed ranges.

Detailed description
[007] Figure 1 illustrates a governor for inline fuel injection pumps, in accordance with one embodiment of this disclosure.

[008] The governor comprises a pair of fly weights 105a and 105b in communication with a cam shaft 102, a pair of link arms 106a and 106b connected to the pair of fly weights 105a and 105b and a connecting rod 110. The governor is characterized by a wedge 115 in contact with the connecting rod 110. The wedge 115 is adapted to move in accordance with movement of the connecting rod 110. The governor is also characterized by a beam 120 comprising a first end and a second end. The first end of the beam 120 is adapted to slide along an inclined portion of the wedge 115. Further, the governor is characterized by a guide element 125 comprising a guide rail 130. The guide element 125 is in contact with the second end of the beam 120. The guide element 125 is adapted to move in vertical direction and horizontal direction. The governor is also characterized by a connecting means 132 adapted to establish connection between a control rack 135 and the guide rail 130. The connecting means is adapted to slide along said guide rail 130. Such sliding of the connecting means along the guide rail 130 enables movement of the control rack 135 in the horizontal direction thereby enabling control of fuel injection quantity.

[009] Referring to Figure 1, the flyweights 105a and 105b are in communication with a cam shaft 102 through a drive shaft 103. The flyweights 105a and 105b are pivotally mounted on a drive shaft 103 that is in communication with the cam shaft 102 of a fuel pump. When the cam shaft 110 rotates, the flyweights 105a and 105b develop a centrifugal force. The centrifugal force, developed by the flyweights 105a and 105b, is transmitted to the connecting rod 110 through the pair of link arms 106a and 106b and hence the connecting rod 110 moves in the horizontal direction.

[0010] Also, the connecting rod 110 is in contact with the wedge 115. The wedge 115 is adapted to move in accordance with the movement of the connecting rod 110. The wedge 110 is also connected to a retainer spring 140.

[0011] The beam 120 comprising a first end and a second end is adapted to slide along the inclined portion of the wedge 110. The first end of the beam 120 is in contact with the inclined portion of the wedge 110.

[0012] The first end of the beam 120 is in contact with the wedge 115 using a rolling contact, for example a roller. The rolling contact enables sliding of the beam 120 along the inclined portion of the wedge 115.

[0013] As the wedge 115 moves horizontally in the direction of the arrow 192, the beam 120 slides vertically upwards in the direction of the arrow 194 because the first end of the beam is in contact with the inclined portion of the wedge 115. Similarly, as the wedge 115 moves horizontally in the direction opposite to the arrow 192, the beam 120 moves vertically downwards in the direction opposite to the arrow 194. Also, as the wedge 115 moves horizontally in the direction of the arrow 192, the retainer spring 140 is compressed. The wedge 115 can move horizontally until the retainer spring 140 is compressed to a maximum extent. The retainer spring 140 is compressed to a maximum extent when the engine speed exceeds a threshold value, for example 2200 rpm.

[0014] The upward and downward movement of the beam 120 moves the guide element 125 in the vertical direction. Similarly, pressing and releasing of the accelerator pedal 160 moves the guide element 125 in the horizontal direction. Such vertical and horizontal movement of the guide element 125 causes the connecting means 132 to slide along the guide rail 130.

[0015] The connecting means 132 is in contact with a control rack 135. Sliding of the connecting means 132 along the guide rail 130 causes movement of the control rack 135 in the horizontal direction. Such horizontal movement of the control rack 135 enables control of fuel injection quantity.

[0016] The connecting means 132 is a ball joint assembly. The ball joint assembly is adapted to absorb axial and lateral forces exerted due to vertical and horizontal movement of the guide element 125. Therefore the movement of the control rack 135 is confined to horizontal direction for controlling fuel injection quantity. However it should be noted that the connecting means 132 is not limited to the ball joint assembly and various other means can also be used as connecting means 132.

[0017] Figure 2A-2D represents exemplary position of the connecting means on the guide rail at various engine speed ranges.

[0018] Figure 2A represents position of the connecting means 132 on the guide rail 130 when engine speed is zero. When the engine speed is zero, no centrifugal force is exerted by the pair of flyweights 105a and 105b, shown in Figure 1, to the connecting rod 110. Hence there is no movement of the guide element 125 in the vertical direction. Also, when engine speed is zero there is no movement of the guide element 125 in horizontal direction since the accelerator pedal 160 is not pressed. The connecting means 132 attains a first position on the guide rail 130, as shown in Figure 1A, when there is no movement of the guide element 125 in both horizontal and vertical direction. Such position of the connecting means 132 on the guide rail 130 holds the control rack 125 at a maximum position which corresponds to maximum fuel injection quantity. The control rack is maintained at the maximum position when the engine speed is zero because maximum fuel quantity can be supplied when the engine is switched on.

[0019] Figure 2B represents position of the connecting means 132 on the guide rail 130 when the engine is operating at low idle speed. In one example, the low idle speed can be 700 rpm. During the low idle speed, the accelerator pedal 160 is not depressed and hence there is no movement of the guide element 125 in horizontal direction. However, during the low idle speed the pair of flyweights 105a and 105b exerts centrifugal force on the connecting rod 110. Due to such centrifugal force, the connecting rod 110 moves in the direction of the arrow 192 as shown in Figure 1. Movement of the connecting rod 110 causes the wedge 115 to move horizontally in the direction of the arrow 192 as shown in Figure 1.

[0020] Such movement of the wedge 115 causes the beam 120 to slide upwards along the inclined portion of the wedge 115. The upward movement of the beam 120 causes the guide element 125 to move upwards in the vertical direction. Such upward movement of the guide element 125 causes the connecting means 132 to slide along the guide rail 130 until it attains a second position as shown in Figure 2B. Such position of the connecting means 132 holds the control rack 135 at a minimum position which corresponds to minimum fuel injection quantity during low idle speed.

[0021] Figure 2C represents position of the connecting means 132 on the guide rail 130 when the engine is operating at full load rated speed. In one example, the full load rated speed can be 2200 rpm. During the full load rated speed, large centrifugal force is exerted by the pair of flyweights 105a and 105b on the connecting rod 110. This force causes movement of the wedge 115 horizontally in the direction of the arrow 192 as shown in Figure 1. Such movement of the wedge 115 moves the beam 120 further upwards along the inclined portion of the wedge 115. The movement of the beam 120 upwards causes movement of the guide element 125 in the vertical direction. Also, at the full load rated speed, the accelerator pedal 160 is pressed completely. Hence, the guide element 125, in addition to vertical movement, also undergoes movement horizontally in the direction of the arrow 196 of Figure 1.

[0022] Such vertical and horizontal movement of the guide element 125 causes the connecting means 132 to slide along the guide rail 130 until it attains a third position as shown in Figure 2C. Such position of the connecting means 132 holds the control rack 135 at a maximum position so that maximum fuel injection quantity is achieved when the engine is operating at full load rated speed.

[0023] Figure 2D represents position of the connecting means 132 on the guide rail 130 when the engine is operating at maximum no load speed. In one example, the maximum no load speed can include a speed range between 2200 rpm and 2400 rpm. When the engine is operating at the maximum no load speed, large centrifugal force is exerted by the pair of flyweights 105a and 105b on the connecting rod 110 which causes movement of the wedge 115 horizontally in the direction of the arrow 192 as shown in Figure 1 until the retainer spring 140 is compressed completely. Such movement of the wedge 115 moves the beam 120 upwards until topmost point in the inclined portion of the wedge 115. Such movement of the beam 120 causes movement of the guide element 125 in the vertical direction.

[0024] The movement of the guide element in the vertical direction causes the connecting means 132 to slide along the guide rail 130 until it attains a fourth position on the guide rail 130 as shown in Figure 2D. Such position of the connecting means 132 holds the control rack 135 at a minimum position so that minimum fuel injection quantity is achieved when the engine is operating at the maximum no load speed. Also, when the engine is operating at maximum no load speed a stop lever may be pulled by manual means or automatic means. When the stop lever is pulled, the guide element 125 undergoes movement in the horizontal direction until a stop spring 145 is compressed completely. The movement of the guide element causes the control rack to attain a position such that fuel injection is cut off.

[0025] By using a wedge, a guide element with a guide rail and a connecting means for establishing connection between the control rack and the governor, large number of mechanical elements for controlling fuel injection quantity is eliminated. Hence, the disclosed governor controls fuel injection quantity with minimum mechanical elements.

[0026] It must be understood that the embodiments explained above are only illustrative and do not limit the scope of the disclosure. Many modifications in the embodiments with regard to material of the wedge, material of the beam, shape of the guide rail are envisaged and form a part of this invention. The scope of the invention is only limited by the claims.