CN1244636A

CN1244636A - Pulling fork and its producing method

Info

Publication number: CN1244636A
Application number: CN 98116293
Authority: CN
Inventors: 增子浩之
Original assignee: Hino Jidosha Kogyo KK
Current assignee: Hino Motors Ltd
Priority date: 1998-08-10
Filing date: 1998-08-10
Publication date: 2000-02-16
Anticipated expiration: 2018-08-10
Also published as: CN1120948C

Abstract

The shift fork machining method can prevent machining deformation caused by the clamping force during cutting and the subsequent heat treatment and results in high rigidity and other performance as well as machining accuracy. The structure of the shift fork has front ends with at least one stepless plane, thickened conneting raised parts and arms for the front ends and reinforcing edge with cross section greater than that of existing shift fork. During machining, the said plane is used as reference plane fixed onto machining drilling die so that the shift fork produces no deformation while being clamped.

Description

Shift fork and manufacture method thereof

The present invention relates to a kind of shift fork and manufacture method thereof, at least one side that particularly relates to a kind of front end at shift fork forms in plane, the arm of connection bump portion and aforementioned front end forms the rib that the big reinforcement of section second moment is used, by with this plane as other side of processing datum cutting, the generation of being out of shape when the machining deformation when preventing cutting due to the clamping force and its after-baking, do not reduce the rigidity of shift fork, increase substantially processability, shift fork that is easy to make and manufacture method thereof.

Shift fork be sealed with the groove (not shown) of the sleeve of speed changer (not shown), this sleeve is slided vertically to carry out two strands of shape parts of variable speed operation, shift fork 1 in the past is in Fig. 6-8, be to form two arm 1b from two strands of shape ground of base portion 1a, 1c, be formed on the base portion 1a shift fork is chimeric, be fixed on the embedding hole 1d on the speed change lever (not shown).

Two arm 1b, the section of 1c is made into the T font that the two sides is formed with rib 1e for the purpose that improves rigidity, with the sealed locking part 1f of the groove of sleeve for can be seamlessly chimeric with this groove, the width that is made into groove by machining accurately is same size.

The machining of locking part 1f is that the reference level 2a with the locking part 1f of shift fork 1 and processing drill jig 2 joins and is placed on after reference level 2a goes up, mounting fixture 3 is joined with rib 1e, and be fixed on the processing drill jig 2 along arrow A direction pushing, two sides 1g with cutting locking part 1f such as milling cutters, 1h is processed into the size identical with the groove of sleeve with the thickness of this locking part 1f.

Shift fork 1 is fixing owing to being the face 1h that the one side of locking part 1f is processed opposite side as benchmark to processing drill jig 2, can not push described another side 1h with mounting fixture 3, can only push the rib 1e that is adjacent, thereby the reference level 2a of processing drill jig 2 and the rib 1e biasing that is pressed, in Fig. 8, because this moment rib 1e and face 1h form the plane, but formation step, when the arrow A direction is pushed mounting fixture 3, at two arm 1b, acting on the bending moment of arrow B and C direction on the 1c respectively, these two arm 1b, 1c is reversed, and a part that becomes face 1g becomes the state that leaves from reference level 2a.

As above-mentioned, owing to be at two arm 1b, 1c is machining face 1h under the state that arrow B and C direction are reversed respectively, so there is the shortcoming that is difficult to high-precision processing locking part 1f.

In addition, after the machining, also to quench, temper and grinding, but distortion residual during owing to machining is when quenching, temper, two arm 1b, 1c further is out of shape, and need carry out grinding for a long time in order to revise this distortion, thereby have poor processability, make many shortcomings in man-hour.

The objective of the invention is to overcome the shortcoming of above-mentioned prior art, at least one side of shift fork front end is formed wheel chair access plane, be fixed on the processing drill jig as machining benchmark with this plane, make shift fork not have the shifting ground and clamp, by preventing the machining deformation due to the clamping force, the distortion when preventing its after-baking, in addition, thus, can reduce the grinding time significantly, improve processibility significantly.

Another purpose is, can utilize said structure, makes shift fork accurately, and thus can be seamlessly closely sealed with the sleeve groove of speed changer, and only just can carry out variable speed operation trippingly with very little power.

Other purpose is, at least one side of shift fork front end is formed the plane, simultaneously, the arm of connection bump portion and front end formed the rib that reinforcement is used, thereby can not reduce the rigidity of shift fork, and improve processibility and machining accuracy.

The present invention be a kind of and sleeve groove speed changer sealed, this sleeve slided vertically and carry out the shift fork of two strands of shapes of variable speed operation, the shift fork of this two strands of shapes has following structure, to form wheel chair access plane with at least one side of the sealed described shift fork front end of the described groove of described sleeve, simultaneously, arm at connection bump portion and described front end forms the rib that the big reinforcement of section second moment is used, with the described plane of described front end as machining benchmark, the other side of the described front end of cutting.

Method of the present invention be a kind of and sleeve groove speed changer sealed, this sleeve slided vertically and carry out the manufacture method of two strands of shape shift forks of variable speed operation, the manufacture method of the shift fork of this two strands of shapes is, to form wheel chair access plane with at least one side of the sealed described shift fork front end of the described groove of described sleeve, behind this plane of cutting, be fixed on the processing drill jig as processing datum with the described plane after this cutting, the other side of the described front end of cutting, the machining deformation when having prevented cutting due to the clamping force.

Fig. 1-Fig. 5 relates to embodiments of the invention, and Fig. 1 is the perspective view of shift fork,

Fig. 2 is the plan view of shift fork,

Fig. 3 is the longitudinal section along III-III among Fig. 2,

Fig. 4 illustrates with mounting fixture shift fork is fixed to the perspective view of processing the drill jig state,

Fig. 5 illustrates with mounting fixture shift fork is fixed to the plan view of processing the drill jig state,

Fig. 6-Fig. 8 is routine in the past, and Fig. 6 illustrates with mounting fixture shift fork is fixed to the perspective view of processing the drill jig state,

Fig. 7 illustrates with mounting fixture shift fork is fixed to the plan view of processing the drill jig state,

Fig. 8 illustrates the plan view that the shift fork bolt is pressed solidly processing drill jig state with clamping force.

Below the present invention will be described for the embodiment shown in reference to the accompanying drawings.In Fig. 1 to Fig. 3, shift fork 10 of the present invention forms wheel chair access plane 10a at least one side of front end, simultaneously, also is formed with the rib 10b that strengthens usefulness.

Shift fork 10 uses high carbon steel, to improve its rigidity and wear resistance through quenching, and be configured as two strands of shapes by forge making, its structure is the sealed installation of sleeve groove (not shown) of front end 10c and speed changer (not shown), and by the operation speed change lever this sleeve is being endwisely slipped, carry out variable speed operation.

The diameter of shift fork 10 is to be formed with the embedding hole 10e that diameter is 20mm on the lug boss 10d about 28mm, the logical speed change lever (not shown) of fixing of this embedding hole 10e interpolation, by this speed change lever is being moved axially,, sleeve is endwisely slipped to carry out variable speed operation by shift fork 10.

It is overhanging circular-arc to become two arm 10f of two strands of shapes to form from lug boss 10d, and be connected with front end 10c, form the reinforcement rib 10b of Fig. 6 at this arm 10f, this is strengthened with much bigger than in the past of height (h) (thickness of arm 10f) of rib 10b above-below direction, for the secondary force of the section of the proportional arm 10f of 3 powers that makes therewith height (h) apart from I (I=bh3/12, at this b is the width of arm 10f) increase and thicken, form and strengthen using rib 10b, the flexural strength of arm 10f is not less than in the past.

The shape of front end 10c forms the L font section that a side is wheel chair access plane 10a.The distance of 2 front end 10c for example is 189.5mm, thickness is 12mm, this front end 10c has that groove with sleeve locks together and the structure of installing, the thickness of front end 10c, for making front end 10c and sleeve groove carry out the seamlessly adaptive machining of implementing accurately, and carry out reprocessing and form.

The manufacture method of shift fork of the present invention be sealed with the sleeve groove of speed changer, this sleeve is slided vertically with the manufacture method of two strands of shape shift forks 10 carrying out variable speed operation, wherein, to form plane 10a with at least one side of the front end 10c of the sealed shift fork 10 of sleeve groove, behind the 10a of this plane of cutting, with the plane 10a after this cutting is processing datum, and be fixed on the processing drill jig, the another side 10g of cutting front end 10c, thus when having prevented cutting by the machining deformation due to the clamping force.

Below, the as above effect of the present invention of structure is illustrated.The thickness of front end 10c is about 12mm, in order to carry out seamlessly adaptive with the sleeve groove, must carry out fine finishing accurately, implement mach detailed description referring to Fig. 4 and Fig. 5, at first, embedding hole 11e is processed into the aperture of regulation, the cutting of being undertaken by milling cutter etc. is processed into plane 10a plane again, to uprightly be arranged on the reference axis 11a break-through embedding hole 10e in the processing drill jig 11 then, plane 10a and reference level 11b are joined and locate, with mounting fixture 12, push rib 10b along arrow D direction, and be fixed on the processing drill jig 11.

With plane 10a as processing datum, by milling cutter etc. the another side 10g cutting of this plane 10a is become plane, because plane 10a does not have step, so seamlessly abut on the reference level 11b tightly, and by mounting fixture 12 by press fit, thereby clamping force can not make arm 10f distortion, thereby prevented machining deformation.

Shift fork 10 is at the two sides of front end 10c 10a, after the 10g cutting, implement quenching, temper, at least the hardness of front end 10c is Vickers hardness 700, then, and with the size grinding embedding hole 10e of regulation and the two sides 10a of front end 10c, 10g, because the machining deformation when having prevented cutting as mentioned above due to the clamping force so only need less grinding capacity, can make easy to manufacture.

The present invention is because as above-mentioned, at least one side of shift fork front end is not formed the plane with having step, and with this plane as machining benchmark be fixed to processing drill jig on, the shift fork shifting ground is clamped, machining deformation when having prevented to clamp due to the clamping force, thus the distortion can prevent its after-baking the time, in addition, owing to can shorten the grinding time significantly, thereby have the effect that can increase substantially processibility.

Adopt said structure, can make shift fork accurately, because can be seamlessly adaptive with the sleeve groove of speed changer, the effect that just can carry out variable speed operation with very little power trippingly had.

In addition, because at least one side of the front end of shift fork is formed wheel chair access plane, simultaneously, compared with the past, the arm of connection bump portion and front end forms the rib of using with its all-in-one-piece reinforcement, thus have the rigidity that can not reduce shift fork, and improve the effect of processability and machining accuracy.

Claims

1. shift fork, this shift fork is shift forks sealed with the sleeve groove of speed changer, two strands of shapes this sleeve being slided vertically carry out variable speed operation, it is characterized in that, at least one side that has with the sealed described shift fork front end of the described groove of described sleeve forms wheel chair access plane, simultaneously, arm at connection bump portion and described front end forms the rib that the big reinforcement of section second moment is used, with the described plane of described front end as machining benchmark, the structure of the other side of the described front end of cutting.

2. the manufacture method of a shift fork, the manufacture method of this shift fork is manufacture method sealed with the sleeve groove of speed changer, that this sleeve is slided vertically carry out two strands of shape shift forks of variable speed operation, it is characterized in that, to form wheel chair access plane with at least one side of the sealed described shift fork front end of the described groove of described sleeve, behind this plane of cutting, be fixed on the processing drill jig as processing datum with the plane after this cutting, the other side of the described front end of cutting, the machining deformation when having prevented cutting due to the clamping force.