CN-113062822-B - Housing for a tappet and tappet

Abstract

The invention relates to a housing for a tappet and a tappet. A housing for a tappet is disclosed, comprising a first section on a driving side and a second section on a driven side in an axial direction of the housing, wherein an outer diameter of the first section of the housing is smaller than an outer diameter of the second section, the first section and the second section are integrally formed, and the housing further comprises a torsion preventing member extending radially outward from a side wall of the housing, the torsion preventing member being formed by punching and bending from the side wall.

Inventors

• LIU ZHENGDONG
• SHEN ZIQI

Assignees

• 舍弗勒技术股份两合公司

Dates

Publication Date

20260508

Application Date

20200102

Claims (7)

1. 1. A housing for a tappet, comprising a first section on a driving side and a second section on a driven side in an axial direction of the housing, wherein an outer diameter of the first section of the housing is smaller than an outer diameter of the second section, an inner wall surface of the first section is flush with an inner wall surface of the second section, the first section and the second section are integrally formed, and the housing further comprises a torsion preventing member extending radially outward from a side wall of the housing, the torsion preventing member being formed by punching and bending from the side wall, a wall thickness of the first section is smaller than a wall thickness of the second section, the torsion preventing member is formed in a junction area between the first section and the second section and extends from the first section, and the torsion preventing member includes a portion from the first section and a portion from the second section.
2. 2. The housing of claim 1, wherein the anti-twist feature is bent at 90 degrees to the sidewall.
3. 3. The housing of claim 1 or 2, wherein the radially outer surface of the second section is a ground surface such that the radially outer surface of the second section has a higher accuracy than the radially outer surface of the first section.
4. 4. The housing according to claim 1 or 2, wherein the outermost edge of the anti-twist member is at least partially arcuate protruding outwardly.
5. 5. The housing of claim 4, wherein two corners of the outermost edges of the anti-twist member are each rounded.
6. 6. The housing of claim 5, wherein an intermediate portion of the outermost edge between the two corners is rounded and the intermediate portion has a radius of curvature greater than the radius of curvature of the corners.
7. 7. A tappet, comprising: the housing according to any one of claims 1 to 6; A pin secured in the bore of the first section of the housing, and A roller having a cylindrical shape and rotatably disposed in the first section of the housing by the pin.

Description

Housing for a tappet and tappet Technical Field The present invention relates to the field of fuel supply. More particularly, the present invention relates to a tappet for a fuel supply system and a housing for the tappet. Background In a fuel supply system of an internal combustion engine, a high-pressure fuel pump is employed to inject fuel into a cylinder. The tappet is disposed between a plunger of the high-pressure fuel pump and a cam of the camshaft, and an axial end of the tappet is inserted into a through hole of the cylinder head. When the internal combustion engine is started, the cam shaft rotates, the cam drives the tappet to reciprocate in the through hole of the cylinder cover, and meanwhile, the plunger is driven to reciprocate. Fig. 1 to 3 show a tappet structure. As shown in fig. 1 to 3, the tappet includes a housing 110, a pin 120, a roller 130, and a rolling body 140. The housing 110 is substantially cylindrical. The housing 110 has two flat portions disposed opposite to each other in an upper half (driving side). Both ends of the pin 120 are inserted into holes of the flat portion, and the pin 120 is fixed to the flat portion. The pin 120 rotatably supports the roller 130 by the rolling bodies 140, so that the roller 130 is rotatably provided on the housing 110. The circumferential surface of the roller 130 is for contact with a cam (not shown) of a cam shaft. To ensure that the roller 130 is always in line contact with the cam, the tappet further includes an anti-twist unit 150. The anti-twisting unit 150 includes a protruding portion 151 and an insertion portion 152. An opening is provided on a sidewall of the housing 110, and the anti-twisting unit 150 is partially inserted into the opening through the insertion portion 152. The protruding portion 151 has a circular arc outer surface. The lifter is for mounting into a through-hole of a cylinder head. A sliding groove is provided on the inner wall of the through hole of the cylinder head. The protruding portion 151 of the anti-twisting unit 150 can be fitted into the sliding groove. When the tappet reciprocates in the through-hole of the cylinder head, the projection 151 also reciprocates in the sliding groove, thereby preventing the tappet from rotating about its axis. The housing 110 is disposed in a contact fit in the through hole and the tolerance range is very small (e.g., only 0.008 μm). Therefore, the manufacturing accuracy of such anti-twist units is very strict, and the manufacturing cost thereof is also very high. The separately provided anti-twist unit needs to be assembled to the housing by an additional process, which also results in an increase in manufacturing time and further increase in cost of the tappet. For this reason, a tappet having a simpler structure is required. Disclosure of Invention It is an object of the present invention to provide a housing and tappet that are simple in construction. It is another object of the present invention to provide a housing and tappet that are reduced in manufacturing costs. One aspect of the present invention provides a housing for a tappet, including a first section located on a driving side and a second section located on a driven side in an axial direction of the housing, wherein an outer diameter of the first section of the housing is smaller than an outer diameter of the second section, the first section and the second section are integrally formed, and the housing further includes a torsion preventing member extending radially outward from a side wall of the housing, the torsion preventing member being formed by punching and bending from the side wall. According to an embodiment of the invention, the anti-twist member extends from the first section. According to an embodiment of the invention, the anti-twist member is formed in the junction area between the first and second sections. According to an embodiment of the invention, the wall thickness of the first section is smaller than the wall thickness of the second section. According to an embodiment of the invention, the anti-twist member is bent at 90 degrees to the side wall. According to an embodiment of the invention, the radially outer surface of the second section is a ground surface, such that the radially outer surface of the second section has a higher accuracy than the radially outer surface of the first section. According to an embodiment of the invention, the outermost edge of the anti-twist member is at least partially arcuate protruding outwards. According to an embodiment of the invention, the two corners of the outermost edge of the anti-twist member are each rounded. According to an embodiment of the invention, the middle portion of the outermost edge between the two corners is rounded and the radius of curvature of the middle portion is larger than the radius of curvature of the corners. Another aspect of the invention provides a tappet comprising a housing according to an embodiment of the invention, a