Claims:We claim:
1. A camshaft lock assembly (100) for a fuel injection pump, comprising:
a flyweight link (102) mounted to said camshaft (104), and
a plug (106) to lock the movement of said camshaft (104), characterized in that:
a cavity (108) arranged on said flyweight link (102); and
a projection (110) complementary to said cavity (108) arranged on said plug (106), to lock said camshaft (104).

2. The camshaft lock assembly (100) as claimed in claim 1, wherein said plug (106) is made of plastic material.

3. The camshaft lock assembly (100) as claimed in claim 1 locks said camshaft (104) at a position comprising a Top Dead Center (TDC), a Bottom Dead Center (BDC), and a position between said TDC and BDC.
, Description:Field of the invention:
[0001] The present invention relates to a camshaft lock assembly for a fuel injection pump.
Background of the invention:
[0002] According to a patent literature WO12080340, a high-pressure pump is disclosed. A high-pressure pump which serves in particular as a radial piston pump or in-line piston pump for fuel injection systems of air-compressing, auto-ignition internal combustion engines comprises a pump assembly and a drive shaft. Here, the pump assembly is driven by the drive shaft via a cam. The cam is joined to the drive shaft. Here, a positively locking connection is formed between the drive shaft and the cam, wherein, to limit a torque transmitted between the drive shaft and the cam, the positively locking connection between the drive shaft and the cam is formed as a predetermined breaking point.
Brief description of the accompanying drawings:
[0003] An embodiment of the disclosure is described with reference to the following accompanying drawing,
[0004] Fig. 1 illustrates a side cut-section view of a camshaft lock assembly for a fuel injection pump, according to an embodiment of the present invention.
Detailed description of the embodiments:
[0005] Fig. 1 illustrates a side cut-section view of a camshaft lock assembly for a fuel injection pump, according to an embodiment of the present invention. The camshaft lock assembly 100 comprises a flyweight link 102 mounted to the camshaft 104, and a plug 106 to lock the movement of the camshaft 104. The flyweight link 102 is rigidly mounted to the camshaft 104 and is removable. The camshaft lock assembly 100 is characterized by a cavity 108 arranged on the flyweight link 102 and a projection 110 complementary to the cavity 108 arranged on the plug 106, to lock the camshaft 104.
[0006] The locking of camshaft 104 is a feature in fuel injection pump to lock the position of the cam at a set position to ease injection timing setting during engine assembly. The feature is used during first installation of the fuel injection pump and service operations, as accuracy of cam position is critical to achieve engine performance as per specifications. The fuel is selected from a group comprising diesel, gasoline and the like. Similarly, the engine is selected from a group comprising spark-ignited engine or a compression ignited engine.
[0007] The plug 106 is made of plastic material. Alternatively, the plug 106 is made of metal with only the projection 110 made out of plastic material. The cavity 108 is a groove or a countersink hole provided on the flyweight link 102.
[0008] The camshaft lock assembly 100 enables locking of the camshaft 104 at a position comprising a Top Dead Center (TDC), a Bottom Dead Center (BDC), and a position between said TDC and BDC. The position corresponds to the position of piston inside the engine cylinder.
[0009] The plug 106 is in the form of fastener having threads on an exterior body. The plug 106 is inserted in a slot (in the shape of a bore) provided on a housing of the fuel injection pump and fastened after projection 110 is inside the cavity 108. The plug 106 is invertible and mountable in same slot, after unlocking the camshaft 104.
[0010] The present invention provides cost effective and simple manufacturing process to an existing design. The existing design comprises a projection 110 on the flyweight link 102 and the cavity 108 on the plug 106 to achieve the desired result. However, the existing design resulted into higher cost of the component due to copper masking of projection 110 during heat treatment to prevent through hardening.
[0011] The present invention provides avoids heat treatment of flyweight link 102 and provides cost saving. Further, cost saving is achieved on machining of surfaces around the flyweight link 102 to get required projection 110. Also, the present invention enables component standardization of flyweight link 102.
[0012] 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.