Claims:We claim:
1. A cam box 10 for calibrating a fuel pump 12, said cam box 10 comprising:
a housing 14;
a cam 16 comprising a cam shaft 18 and a cam lobe 20 mounted on said cam shaft 18; characterized in that
an L-shaped plate 22 coupled to said housing 14;
a flanged member 24 coupled to said housing 14 and to said L-shaped plate 22 and adapted to secure said cam 16 in said cam box 10; and
wherein a first portion of said cam shaft 18 is inserted within said flanged member 24, and wherein a second portion of said cam shaft 18 is inserted within said housing 14.

2. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 wherein the first portion of said cam shaft 18 is inserted within said flanged member 24 and rotates within said flanged member 24 via a first bush bearing 26.

3. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 wherein the second portion of said cam shaft 18 is inserted within said housing 14 and rotates within said housing 14 via a second bush bearing 28.

4. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 2 and 3 wherein said first bush bearing 26 and said second bush bearing 28 may be removably coupled to said cam shaft 18.

5. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 further comprising a plug 34 inserted within said housing 14 and proximate to the second portion of said cam shaft 18.

6. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 further comprising a coupling 30 secured to said cam shaft 18 via a screw 31, said coupling 30 adapted to rotate said cam shaft 18.

7. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 wherein said housing 14 is coupled to said L-shaped plate 22 by means of at least one bolt 32.

8. The cam box 10 for calibrating a fuel pump 12 in accordance with Claim 1 wherein a part of said flanged member 24 is inserted within a groove defined in said L-shaped plate 22. , Description:Field of the invention:
[0001] This disclosure relates to a cam box, and more particularly to a cam box for calibrating a fuel pump.
Background of the invention:
[0002] Chinese Patent Application Number 203627056U describes a utility model that discloses an assembly part of a fuel injection pump cam box of a diesel engine. The assembly part consists of a roller bushing, a roller, a roller body, the cam box, an insert, a spring, an upper spring seat and a lower spring seat, wherein a roller body guide cylinder is fixed on the cam box in an interference fit manner. An O-ring is installed at an installation surface gap of the roller body guide cylinder and the cam box, and an oil blocking umbrella is installed at the lower end of the roller body guide cylinder. According to the assembly part, the problem of jumping of engine oil in the assembly part of the fuel injection pump cam box of the diesel engine is solved, mixing of the engine oil and fuels is avoided, unnecessary waste of the fuels is reduced, and excess losses of the engine oil are reduced. Meanwhile, the cam box in the assembly part of the fuel injection pump cam box is simple in process and convenient to machine.

Brief description of the accompanying drawing:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing:
[0004] Figure 1 illustrates a block diagram of a cam box for calibrating a fuel pump.

Detailed description of the embodiments:
[0005] A cam box 10 for calibrating a fuel pump 12 is described. The cam box 10 comprises a housing 14 and a cam 16 comprising a cam shaft 18 and a cam lobe 20 mounted on the cam shaft 18. An L-shaped plate 22 is coupled to the housing 14. A flanged member 24 is coupled to the housing 14 and to the L-shaped plate 22, and adapted to secure the cam 16 in the cam box 10. A first portion of the cam shaft 18 is inserted within the flanged member 24, and wherein a second portion of the cam shaft 18 is inserted within the housing 14.

[0006] Figure 1 illustrates a cam box 10 for calibrating a fuel pump 12. The cam box 10 includes a housing 14 within which the fuel pump 12 containing a roller tappet is inserted. Moreover, a cam 16 is inserted within the housing 14 of the cam box 10. The cam 16 comprises a cam shaft 18 and a cam lobe 20 that is formed on the cam shaft 18. A plug 34 is inserted within the housing 14 and is located proximate to an end of the cam shaft 18. The plug 34 facilitates sealing the cam shaft 18 such that lubricating oil does not escape from the housing 14 of the cam box 10. The cam lobe 20 is in contact with the roller tappet of the fuel pump 12 such that the cam lobe 20 facilitates supplying pressurized fuel from the fuel pump 12 when the cam shaft 18 is rotated via a driving mechanism.

[0007] An L-shaped plate 22 is coupled to the housing 14 of the cam box 10. A first side of the L-shaped plate is coupled to the housing 14. A bolt 32 is used to secure the housing 14 to the L-shaped plate 22. A second side of the L-shaped plate 22 is coupled to a solid supporting surface via a plurality of bolts for securely fastening the L-shaped plate 22. A first bush bearing 26 is coupled to the cam 16. The first bush bearing 26 is coupled to the cam 16 by press fitting the first bush bearing 26 to the cam shaft 18. A second bush bearing 28 is coupled to the cam 16 by press fitting the second bush bearing 28 to the cam shaft 18. A flanged member 24 is coupled to the housing 14. A first portion of the cam 16 is inserted within an opening defined in the flanged member 24 such that the flanged member 24 surrounds the first bush bearing 26. A second portion of the cam 16 is inserted within an opening defined in the housing 14 such that the housing 14 surrounds the second bush bearing 28. The flanged member 24 is coupled to the L-shaped plate 22 by inserting the flanged member 24 within a groove defined in the L-shaped plate 22. The flanged member 24 facilitates securing the cam 16 within the housing 14 of the cam box 10.

[0008] The cam box 10 includes a coupling 30. The coupling 30 is secured to the cam shaft 18 by means of a screw 31. The coupling 30 is coupled to a driving mechanism which supplies mechanical power to the coupling 30 by rotating the coupling 30 about a horizontal axis. Based on the power that is received from the coupling 30, the cam 16 rotates thereby causing the cam lobe 20 to rotate about a horizontal axis. The rotation of the cam lobe 20 causes the roller tappet that is in contact with the cam lobe 20 to reciprocate. By measuring the length of the stroke of the roller tappet, the fuel pump 12 may be tested for calibration.

[0009] The working of the cam box 10 is described as an example. The L-shaped plate 22 is coupled to the housing 14 and secured thereto by means of the bolt 32. The flanged member 24 is coupled to the housing 14 and secured to the L-shaped plate 22 by inserting the flanged member 24 within a groove defined in the L-shaped plate 22. The coupling 30 is coupled to the cam 16 by inserting the cam shaft 18 within the coupling 30 and securing it by means of the screw 31. Specifically, the screw 31 is coupled to an end of the cam shaft 18 and screwed on to screw threads defined on the cam shaft 18 for securing the coupling 30 to the cam shaft 18. The cam 16 is inserted within the housing 14 of the cam box 10 such that the first portion of the cam shaft 18 is inserted within the flanged member 24, while a second portion of the cam shaft 18 is inserted within the housing 14. The cam lobe 20 that is defined between the first portion of the cam shaft 18 and the second portion of the cam shaft 18 rotates within the housing 14. The rotation of the cam lobe 20 causes the roller tappet of the fuel pump 12 to reciprocate within the housing 14 of the cam box 10.

[00010] When it is required to disassemble the cam box 10, the coupling 30 is disassembled from the cam shaft 18 by removing the screw 31. Therein, the L-shaped plate 22 is disassembled from the housing 14 by withdrawing the bolt 32 from the housing 14. The flanged member 24 is released from the housing 14 by withdrawing the bolts that secures the flanged member 24 to the housing 14. The cam 16 is finally withdrawn from the housing 14. When the first bush bearing 26 and the second bush bearing 28 of the cam 16 need to be replaced when they wear out, the first bush bearing 26 and the second bush bearing 28 that are in a press fit arrangement with the cam shaft 18 are removed. The first bush bearing 26 and the second bush bearing 28 are then replaced before inserting the cam 16 within the housing 14 of the cam box 10. The flanged member 24 is inserted within the housing 14 and fastened by means of bolts, and the L-shaped plate 22 is fastened to the flanged member 24. Finally, the coupling 30 is secured to the cam shaft 18 by means of the screw 31 and the housing 14 is secured to the L-shaped plate via the bolt 32.

[00011] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.