CN204663603U

CN204663603U - A kind of camshaft

Info

Publication number: CN204663603U
Application number: CN201520386579.XU
Authority: CN
Inventors: 刘振锋; 覃文; 王倩; 廖乾畅
Original assignee: Guangxi Yuchai Machinery Co Ltd
Current assignee: Guangxi Yuchai Machinery Co Ltd
Priority date: 2015-06-08
Filing date: 2015-06-08
Publication date: 2015-09-23
Anticipated expiration: 2025-06-08

Abstract

The utility model discloses a kind of camshaft, camshaft is provided with thrust surface and multiple spaced cam, and cam comprises: working part, and working part contacts with tappet; Two assisting sections, two assisting sections are symmetricly set on the both sides of working part, the shape of the longitudinal section of assisting section but scaled down identical with the shape of the longitudinal section of working part, makes the distance on the edge of the end face of assisting section between each point and the axis of camshaft be less than distance between point corresponding on the outer surface of working part and the axis of camshaft.The cross section of cam of the present utility model is high in the middle and low on both ends, the both sides of cam are avoided to there is sharp limit and cause cam and tappet mutually to wear and tear, such structure makes the process medium plain emery wheel of grinding cam must position relative to thrust surface simultaneously, just can guarantee the offset of cam and tappet, improve the quality of processing of camshaft, make the degree of wear of the multiple cams on same camshaft close, improve the working life of camshaft and tappet.

Description

A kind of camshaft

Technical field

The utility model relates to engine art, particularly a kind of camshaft.

Background technique

Under Fig. 1 and 2 is the cam shaft for diesel engine installment state of prior art, body front-end face 1 abuts with the thrust surface 601 of camshaft 60.For the cam 20 near body front-end face 1, the edge of cam 20 both sides of camshaft 60 is sharp limit 201, although also will remove the burr on point limit, cam both sides after grinding, deburring is more difficult, and inefficiency.

Tappet 5 is smooth surface with the working surface 51 of cam contact, but due to cam both sides be sharp limit, and cam is irregularly shaped in a circumferential direction, in practical work process, when tappet is stressed, the sharp limit of cam both sides easily forms wedge angle, the working surface of scratch tappet.Tappet surface damage, damages cam face conversely, thus exacerbates the mutual wearing and tearing of cam and tappet.

In order to reduce the wearing and tearing of cam and tappet, usually cam 2 and tappet 5 is made to have certain offset Α 0, the difference of the distance Α 2 namely between the center line of cam 20 and thrust surface 601 and the distance Α 1 between the central axis of tappet hole 4 and body front-end face 1, rotation is to a certain degree had, therefore the contact surface even wearing of tappet 5 and cam 20 after making tappet 5 be subject to the frictional force of cam 20.Because body 3 is processed by special machine machining center, the central axis of tappet hole 4 and the distance Α 1 of body front-end face 1 are definite values, and installment state lower body front-end face 1 abuts with the thrust surface 601 of camshaft 60.Thus, the distance between the central axis of cam 20 and body front-end face 1 is determined by distance Α 3, Α 4 between the edge of cam 20 both sides and thrust surface 601 indirectly.But, in the operation of grinding cam, the working surface of emery wheel 70 is plane, do not need in grinding process to consider the position of emery wheel 70 relative to thrust surface 601, therefore the distance between the both sides of cam and thrust surface cannot be ensured in grinding process, cause the deviation of distance Α 3, Α 4 comparatively large, the mobility scale of the distance Α 0 (i.e. offset) of the central axis of cam 20 and the central axis of tappet hole 4 is larger.Like this, on same camshaft, the offset of some cams meets size requirement, and corresponding tappet rotates, and the offset of some cams to be less than predetermined value be even zero, corresponding Tappet Rotation is very little or do not rotate, the degree of wear inconsistency of the multiple cams therefore on same camshaft, shortens the working life of camshaft and tappet, and the roughness of engine also may be caused fixed, degradation, to diesel engine performance and reliability unfavorable.

The information being disclosed in this background technique part is only intended to increase the understanding to general background of the present utility model, and should not be regarded as admitting or imply in any form that this information structure has been prior art that persons skilled in the art are known.

Model utility content

The purpose of this utility model is to provide a kind of camshaft, thus the sharp limit overcoming prior art convexity wheel shaft causes that cam and tappet wear and tear mutually, diesel engine performance and the bad defect of reliability.

For achieving the above object, the utility model provides a kind of camshaft, and camshaft is provided with thrust surface and multiple spaced cam, and cam comprises: working part, and working part contacts with tappet; Two assisting sections, two assisting sections are symmetricly set on the both sides of working part, the shape of the longitudinal section of assisting section but scaled down identical with the shape of the longitudinal section of working part, makes the distance on the edge of the end face of assisting section between each point and the axis of camshaft be less than distance between point corresponding on the outer surface of working part and the axis of camshaft.

Preferably, in technique scheme, the axial sides of assisting section is arc-shaped.

Compared with prior art, the utility model has following beneficial effect:

The cross section of cam of the present utility model is high in the middle and low on both ends, the both sides of cam are avoided to there is sharp limit and cause cam and tappet mutually to wear and tear, such structure makes the process medium plain emery wheel of grinding cam must position relative to thrust surface simultaneously, just can guarantee the offset of cam and tappet, improve the quality of processing of camshaft, make the degree of wear of the multiple cams on same camshaft close, improve the working life of camshaft and tappet, also improve the functional reliability of diesel engine; In the processing method of camshaft, eliminate the operation of the burr removing cam nose limit, improve work efficiency, reduce cost.

Accompanying drawing explanation

Fig. 1 is the camshaft of prior art and the erection drawing of body.

Fig. 2 is the grinding schematic diagram of the camshaft of prior art.

Fig. 3 is the erection drawing according to camshaft of the present utility model and body.

Fig. 4 is the grinding schematic diagram according to camshaft of the present utility model.

Fig. 5 is the local structural graph according to cam of the present utility model.

Main Reference Numerals illustrates:

1-body front-end face, 2-cam, 21-working part, 22-assisting section, 23-transition arc, 24-height difference, 3-body, 4-tappet hole, 5-tappet, 51-working surface, 6-camshaft, 61-thrust surface, 7-emery wheel, 20-cam, 201-point limit, 60-camshaft, 601-thrust surface, 70-emery wheel.

Embodiment

Below in conjunction with accompanying drawing, embodiment of the present utility model is described in detail, but is to be understood that protection domain of the present utility model not by the restriction of embodiment.

Clearly represent unless otherwise other, otherwise in whole specification and claims, term " comprise " or its conversion as " comprising " or " including " etc. by be understood to include the element of stating or constituent element, and do not get rid of other element or other constituent element.

As shown in Figures 4 and 5, the camshaft 6 according to the utility model embodiment is provided with thrust surface 61, and under installment state, thrust surface 61 abuts with the body front-end face 1 of body 3.Camshaft 6 is interval with multiple cam 2, the position of each cam 2 is corresponding with the position of the tappet 5 in the tappet hole 4 being arranged on body 3.As shown in Figure 4, on body 3, the distance between the central axis of body front-end face 1 and tappet hole 4 is Α 1 ± α 1.

As shown in Figure 5, cam 2 comprises working part 21 and two assisting sections 22.As shown in Figure 3, working part 21, for contacting with the working surface 51 of tappet 5, promotes tappet 5 and works.The width L1 of working part 21 is identical with the width of cam of the prior art.As shown in Figure 5, two assisting sections 22 are symmetricly set on the both sides of working part 21, the shape of the longitudinal section of assisting section 22 but scaled down identical with the shape of the longitudinal section of working part 21 (is equivalent to working part profile toward the certain distance of bias internal, as 2mm), the distance between each point on the edge of the end face 221 (plane perpendicular to the axis of camshaft 6) of assisting section 22 and the axis of camshaft 6 is made to be less than distance between point corresponding on the outer surface of working part 21 and the axis of camshaft 6, as shown in Figure 5.The axial sides 23 of assisting section 22 is in arc-shaped.

The processing method making camshaft of the present utility model comprises the steps:

1) rolling is carried out to the blank of camshaft;

2) roughing is carried out to the blank after rolling, form thrust surface 61 and multiple cam 2;

3) make the emery wheel 7 being used for machining cam, the shape and size of emery wheel 7 are corresponding with the shape and size of the cross section of cam 2, and namely the finished surface of emery wheel 7 is groove-like, and the middle part of groove is cylindric, and both sides are arc-shaped;

4) grinding is carried out to multiple cam, make the center line of each cam be corresponding predeterminable range with the distance of thrust surface.For the cam 2 near thrust surface 61, the center line of emery wheel 7 and the distance of thrust surface 61 are Α 2 ± γ 1, distance between the central axis and body front-end face 1 (i.e. thrust surface 61) of tappet hole 4 is Α 1 ± α 1, offset is Α 0 ± λ 1.Meanwhile, the width of working part 21 is L1 ± u1.

The aforementioned description to concrete exemplary of the present utility model is to illustrate and the object of illustration.These descriptions not want the utility model to be defined as disclosed precise forms, and obviously, according to above-mentioned instruction, can much change and change.The object selected exemplary embodiment and describe is to explain certain principles of the present utility model and practical application thereof, thus those skilled in the art can be realized and utilize various different exemplary of the present utility model and various different selection and change.Scope of the present utility model is intended to limited by claims and equivalents thereof.

Claims

1. a camshaft, described camshaft is provided with thrust surface and multiple spaced cam, and it is characterized in that, described cam comprises:

Working part, described working part contacts with tappet;

Two assisting sections, described two assisting sections are symmetricly set on the both sides of described working part, the shape of the longitudinal section of described assisting section but scaled down identical with the shape of the longitudinal section of described working part, makes the distance on the edge of the end face of described assisting section between each point and the axis of described camshaft be less than distance between point corresponding on the outer surface of described working part and the axis of described camshaft.

2. camshaft according to claim 1, is characterized in that, the axial sides of described assisting section is arc-shaped.