JPH09144877A - Shift operation member of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the working manhours of a shift operation member, and improve the roductivity by forming a hard alumite coating film at least in a sliding contact part after die-cast molding is performed on a shift arm, a shift block or a shift fork by aluminium alloy. SOLUTION: When it is performed on a shift arm 20 as a shift operation member, die-cast molding is performed on a shift arm 20 by aluminium alloy whose silicon content is restrained to about 0.3% or less. Machine work is performed on an inserting hole for a shift rod, a hole 20d of a fixing spring pin to the shift rod and a two-stage hole composed of a small diameter hole and a large diameter hole of a plunger and a spring, and the whole shape is finished. Afterwards, the whole surface of the shift arm 20 is anodically oxidized in electrolyte, and a hard alumite coating film (a hard anodic oxidation coating) is formed. Hard alumite processing may be performed on only two places of a lower end projecting part particularly required to improve surface hardness and a recessed claw part 20b on the upper end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called shift operating member of a shift arm, a shift block, and a shift fork used in a transmission, and more specifically, to a shift operating member that fits into or contacts another shift operating member. The present invention relates to a shift operation member having a sliding contact portion that slides by sliding.

[0002]

2. Description of the Related Art For example, the above-mentioned shift fork is mounted on a shift rod and transmits an operating force from a shift lever manually operated by a driver during a gear shift to a hub sleeve through the shift rod and the shift fork in order. Since both side claws of the arcuate tip of the shift fork are in sliding contact with the hub sleeve that rotates with the driving of the engine,
Wear resistance is required.

Therefore, conventionally, as described in Japanese Patent Publication No. 62-8807, carbon steel (S48C) is forged and then machined to finish into a shift fork shape, and both lower ends which are sliding contact parts. There is proposed a method of forming a thermal spray coating by plasma spraying the sliding claws of the parts after induction hardening, and then performing plasma treatment and using molybdenum as a spray material. Further, as described in Japanese Patent Application Laid-Open No. 4-78374, a method of forming the sliding claw portion with a carbon fiber reinforced carbon sintered body has been proposed. In addition, 16 silicon
A method of die casting a shift fork with a high silicon aluminum alloy containing ~ 18% has been proposed.

The shift arm and shift block are made of ferrous metal (SC, SF, FCD, FCM).
(P, sintered alloy) to form the main body by forging, etc., and then machine it, and then perform induction hardening, soft nitriding, carburizing or chilling on the sliding contact part. Therefore, a method for improving wear resistance and pressure resistance is generally implemented. Further, such a surface treatment method is similarly carried out for a shift fork made of an iron-based metal material.

[0005]

However, the shift fork described in the above publication and the conventional shift arm described above have room for improvement in the following points.

Shift operation members manufactured by using iron-based metal materials, such as the shift fork described in Japanese Patent Publication No. Sho 62-8807 and Japanese Patent Application Laid-Open No. 4-78374, have a large number of cutting process steps and are troublesome to manufacture. Takes. In addition, since the specific gravity is large, it is difficult to reduce the weight.

A shift fork die-cast with a high silicon aluminum alloy having a high silicon content is relatively easy to manufacture and can obtain the necessary wear resistance of the sliding contact portion, but it is weak against impact and lacks tenacity. In order to obtain the required rigidity and strength, the shift fork must be made large as a whole, which hinders downsizing of the transmission.

The present invention has been made in view of the above-mentioned points, and it is possible to reduce the number of processing steps of the shift operating members of the shift arm, the shift block, and the shift fork to improve the productivity, and to reduce the weight and size. An object is to provide a shift operation member for a machine.

[0009]

In order to solve the above problems, a shift operating member of a transmission of the present invention is intended for a shift arm, a shift block and a shift fork having a sliding contact portion, and a) the shift operation. The member is die-cast with an aluminum alloy, and b) at least the sliding contact portion of the die-cast shift operating member is hard-anodized (hard-anodized) to form a hard-anodized film (hard-anodized film) on the surface. Is formed.

By the die cast molding of the above a), the entire shape of the shift operating member is almost completed, and it is only necessary to machine (cut) the portions such as holes as necessary, and the productivity is improved. Further, by the hard alumite treatment of the above b), a hard alumite coating is formed on at least the surface of the sliding contact portion, so that the surface hardness of the aluminum alloy becomes hard to or near the hardness of the surface treatment of the iron-based material.
As a result, in the case of a shift arm and a shift block, particularly the pressure resistance and wear resistance (hertz stress resistance) of the sliding contact portion are improved, and long-term use is possible. Especially wear resistance of parts (PV resistance
The value) is improved and long-term use becomes possible. Moreover, since each shift operating member is made of an aluminum alloy, the weight is lighter and the weight is lighter than that of the iron-based metal material. Further, if the entire member is subjected to the hard alumite treatment, the rigidity and strength of the entire member are improved, which is useful for reducing the size and weight. The surface hardness of the sliding contact portion is improved from JIS hardness RC15-20 of the surface of the aluminum alloy to RC50 or more.

According to a second aspect of the present invention, the silicon content of the shift operating member may be 10% or less, preferably 1% or less.

The reduction of the silicon content of the shift operating member according to this structure improves the strength against impact, which is more advantageous for downsizing and weight saving. At the same time, the thickness of the hard anodized film increases in proportion to the decrease in the silicon content, and the pressure resistance or wear resistance continues for a longer period of time. Hard anodized film has a silicon content of 16
% Of high silicon ADC14 (aluminum die cast) does not reach 20 microns, but the ADC10 and ADC12 (ordinary aluminum die cast) with a silicon content of 7.5-12% reach about 20 microns and the silicon content ADC6, ADC5 less than 1.0%
Then, it becomes 30 to 50 microns.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a shift operating member of a transmission according to the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing the whole of the transmission according to the present embodiment. In FIG. 1, the left side on the same axis is an input shaft 2 and the right side is an output shaft 3, which are parallel to the lower side of these shafts 2 and 3. Counter shaft 4
Each of the transmissions 1 is rotatably supported in the transmission 1. A plurality of shift rods 5 are arranged in parallel above the shafts 2 and 3 so as to be movable in the longitudinal direction. A shift fork 6 is mounted on the shift rod 5 via a spring pin 7, and both side claws 6a (FIG. 6 (a)) of the arc-shaped lower end (tip) of the shift fork 6 are placed on the output shaft 3. It is engaged with the hub sleeve 8. Also shift rod 5
The shift block 9 is mounted on the upper side by a spring pin 10 (FIG. 3) adjacent to the shift fork 6. Therefore, the shift control shaft 11 is rotatably disposed above the shift rod 5 at the center of the upper end of the transmission 1 and orthogonal to the shift rod 5. On the shift control shaft 11, the shift internal lever 1
2 is mounted movably in the longitudinal direction.

A select external lever 13 is provided on the left side of the shift control shaft 11 outside the transmission 1.
Is rotatably supported about a vertical axis, and a select internal lever 14 at the lower end of the select external lever 13 is engaged with the shift internal lever 12. With this configuration, when the select external lever 13 is turned by a predetermined angle, the shift internal lever 12 moves a predetermined distance along the shift control shaft 11 in accordance with the rotation of the select internal lever 14, and the target shift block 9 or shift arm is moved. Two
0 is engaged. Furthermore, shift control shaft 1
Shift external lever 11a fixed to 1
When is rotated, the shift internal lever 12 is rotated, and the shift block 9 or the shift arm 20 moves the shift fork 6 mounted on the shift rod 5 in the axial direction of the shift rod 5 and engages with the shift fork 6. Change the hub sleeve 8 by moving it.

FIG. 2 is an enlarged cross-sectional view near the upper center of the transmission 1, which is a cross-sectional view taken along the line II-II of FIG. 3, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. As shown in FIG. 3, four shift rods 5 are arranged at equal intervals in the width direction, and on each of the three shift rods 5 on the left side, a shift block 9 ′ is arranged in order from the left end,
9, 9 "are mounted by spring pins 10 respectively, a shift arm 20 (lever-shaped shift block) is mounted by spring pins 21 on the right end shift rod 5, and lower end protrusions 20a (sliding contact portions) of shift arms 20 are mounted. ) Is engaged with a concave claw portion of a shift block (not shown), and coil springs are provided on both sides so as to sandwich the shift internal lever 12 on the shift control shaft 11 orthogonal to the shift rods 5. 15 is disassembled, shift internal lever 12
To return to the neutral state. When the shift internal lever 12 is engaged with the upper end concave claw portion (sliding contact portion) 20b of the right end shift arm 20, the plunger urged outward through the spring 17 in the shift arm 20. 16 is pushed against the spring 17.

As shown in FIG. 2, the shift rod 5 has a detent ball 18 urged downwardly through a day tent spring 19 and a fitting groove provided at the tip end portion of the shift rod 5 with a gap. Positioned by fitting to 5a. Reference numeral 22 in FIGS. 2 and 3 is an oil seal.

The shift operation member of the transmission 1 according to the present invention, here, the shift arm 20, the shift block 9 and the shift fork 6 have the following features.

A) Shift arm: As shown in FIGS. 4 (a) to 4 (c), the shift arm 20 has a known structure, but the die is made of an aluminum alloy having a silicon content of 0.3% or less. After cast molding, the through hole 20c for the shift rod 5 (Figs. 2 and 3), the hole 20d of the fixing spring pin 21 (Fig. 3) for the shift rod 5, the plunger 16 (Fig. 3) and the spring 17 (Fig. 3). The two-stage hole 20e consisting of the small-diameter hole and the large-diameter hole in) is machined to finish the entire shape. Then, in this example, the entire surface of the shift arm 20 made of an aluminum alloy having a silicon content of 0.3% or less is anodized in an electrolytic solution to form a hard anodized film of about 40 to 50 microns thick ( Hard anodized film) is formed. Since the places where the surface hardness needs to be particularly improved by such a hard alumite treatment are the lower end protrusions 20a to which the surface pressure is locally applied and the concave claws 20b at the upper end, only these two places are hard alumite treated. Good. Needless to say, in order to improve the rigidity or reduce the size of the entire member, the hard alumite treatment is performed on the entire member as in the present embodiment. The reference numeral 20f in the drawing is a rotation preventing groove.

The surface hardness obtained by the above hard alumite treatment is almost the same (RC50 or more) as when the surface is induction hardened after being formed of an iron-based metal. Therefore, particularly, the lower end protrusion 20a and the upper end concave claw 2 are provided.
The pressure resistance and wear resistance of 0b are greatly improved, and long-term use becomes possible.

B) Shift block: As shown in FIGS. 5 (a) to 5 (c), the shift block 9 has a known structure, but the die is made of an aluminum alloy having a silicon content of 1.0% or less. After cast molding, shift rod 5
The insertion hole 9c (FIGS. 2 and 3) and the hole 9d of the fixing spring pin 10 (FIG. 3) for the shift rod 5 are machined to complete the entire shape. Then, in this example, the entire surface of the shift block 9 is anodized in an electrolytic solution to form a hard anodized film (hard anodized film) having a thickness of about 30 to 40 microns. Needless to say, the concave claw portion (sliding contact portion) 9a at the upper end may be hard-anodized at places where the surface hardness needs to be improved by such hard-anodized treatment.

The surface hardness obtained by the above hard alumite treatment is almost the same as the surface treatment of iron-based materials (RC50).
Becomes Therefore, particularly, the pressure resistance of the concave claw portion 9a is significantly improved and the long-term use becomes possible.

C) Shift fork: As shown in FIGS. 6 (a) to 6 (c), the shift fork 6 has a known structure, but the die is made of an aluminum alloy having a silicon content of 1.0% or less. After cast molding, the insertion hole 6c for the shift rod 5 (FIGS. 2 and 3) and the hole 6d of the fixing spring pin 7 for the shift rod 5 are machined to complete the entire shape. Then, in the present example, lower end both side claw portions (sliding contact portions) 6a of the arc-shaped frame portion of the shift fork 6 using an aluminum alloy having a silicon content of 1.0% or less.
Is anodized in an electrolytic solution to form a hard anodized film (hard anodized film) having a thickness of about 30 to 40 microns.

The surface hardness obtained by the above hard alumite treatment is almost the same as the surface treatment of iron-based materials (RC50).
Therefore, the wear resistance of the claw portions 6a on both sides is significantly improved, and long-term use becomes possible.

[0025]

As is apparent from the above description,
The shift operation member of the transmission according to the present invention has the following effects.

(1) Since a shift operation member such as a shift block can be die-cast molded, the number of man-hours required for machine (cutting) processing is minimized, productivity is improved, and mass production becomes possible. Cost can be reduced.

Further, since a hard alumite coating is formed on at least the surface of the sliding contact portion of the shift operating member, the surface hardness of the aluminum alloy becomes almost equal to the hardness when carburizing or induction hardening, so that the shift arm and In the case of a shift block, the sliding contact part has improved pressure resistance and wear resistance, enabling long-term use, and in the case of a shift fork, the sliding contact part has improved wear resistance, enabling long-term use. become.

Further, since the material of each shift operating member is made of aluminum alloy, the weight is lighter and lighter than that of iron-based metal.

(2) Since the shift operating member according to claim 2 has a very low silicon content, it has a high tenacity, is easy to downsize, and promotes weight reduction.

Further, as the silicon content is reduced, the thickness of the film formed when the surface of the aluminum die cast molded product is hard-anodized is increased, the surface hardness is improved, and the product can be used for a long time. become.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing an entire transmission according to an embodiment of the present invention.

2 is an enlarged cross-sectional view near the upper center of the transmission shown in FIG.
The II-II line cross section of FIG. 3 is represented.

3 is a sectional view taken along line III-III in FIG.

4 (a) is a front view of a shift arm according to an embodiment of the present invention, FIG. 4 (b) is a plan view thereof, and FIG. 4 (c) is FIG. 4 (a).
FIG. 7 is a sectional view taken along line cc of FIG.

5 (a) is a front view of a shift block according to an embodiment of the present invention, FIG. 5 (b) is a plan view thereof, and FIG. 5 (c) is a left side view thereof.

6 (a) is a front view of a shift fork according to an embodiment of the present invention, FIG. 6 (b) is a sectional view taken along line bb of FIG. 6 (a),
FIG. 6C is a left side view of the same.

[Explanation of symbols]

 1 transmission 5 shift rod 6 shift fork 6a claw portion (sliding contact portion) 8 hub sleeve 9 shift block 9a concave claw portion (sliding contact portion) 20 shift arm 20a lower end projection (sliding contact portion) 20b concave claw portion (sliding contact) (Contact part)

Claims (2)

[Claims] 1. A shift arm, a shift block or a shift fork as a shift operating member having a sliding contact portion is die-cast with an aluminum alloy, and at least the sliding contact portion of the die cast molded shift operating member is made of hard alumite. A shift operation member for a transmission, characterized by being treated to form a hard alumite coating on the surface. 2. The shift operating member for a transmission according to claim 1, wherein the silicon content of the shift operating member is 10% or less, preferably 1% or less.