JP2004286096A - Shift shaft manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shift shaft manufacturing method having improved productivity while securing the function of a sift shaft. <P>SOLUTION: The method comprises executing in sequence a step (Fig.A) of dividing the shift shaft 10 to which shift operating force is transmitted, into a plurality of parts and mutually integrating shaft divided parts 12, 14 having a protruded portion 12A and a recessed portion 14A fittable to the opposed ends by fitting the protruded portion 12A and the recessed portion 14A thereto, a step (Fig.B) of forming a pin hole 16 passing through joint portions of the shaft divided parts 12, 14 and driving a pin 18 thereinto for preventing their looseness, and a step (Fig.C) of polishing a plurality of journaled portions 20A-20D of the shift shaft 10 so as to be approximately concentric. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a shift shaft, and more particularly, to a technique for improving the manufacturability.
[0002]
[Prior art]
In the field of heavy commercial vehicles, as disclosed in Non-Patent Document 1, a multi-stage transmission in which the gear ratio is crossed while having a wide gear ratio is mounted in order to flexibly cope with an operation state that changes depending on a load capacity or the like. Often. In the multi-stage transmission, a multi-stage transmission is realized by shifting each speed stage of the main transmission by half a step toward a high speed side or a low speed side by an auxiliary transmission provided on an input side of the main transmission.
[0003]
[Non-patent document 1]
"Maintenance Manual Heavy Truck Chassis (A790)", Nissan Diesel Industries, Ltd. Customer Service Department, June 2000 [0004]
[Problems to be solved by the invention]
By the way, in the multi-stage transmission, due to the layout of the vehicle, as shown in FIG. 3, the air cylinders 1A and 1B provided on the output side (rear part) of the main transmission change the speeds of the main transmission and the sub-transmission. Is performed. For this reason, the shift shaft 3 that transmits the output of the air cylinder to the shift fork 2 of the auxiliary transmission is much longer than the other shift shafts 4A to 4C. Therefore, when manufacturing the shift shaft 3 for the auxiliary transmission, machining must be performed while paying attention to bending or bending, and the manufacturing time is increased. I was
[0005]
SUMMARY OF THE INVENTION In view of the above-mentioned conventional problems, an object of the present invention is to provide a shift shaft manufacturing method that improves the manufacturability while reviewing the method of manufacturing the shift shaft while ensuring the function of the shift shaft.
[0006]
[Means for Solving the Problems]
For this reason, in the invention according to the shift shaft manufacturing method according to claim 1, the shift shaft to which the shift operation force is transmitted is divided into a plurality of parts, and the convex part and the concave part which can be fitted to the facing end are formed respectively. A step of integrating the shaft divided body by fitting the convex portion and the concave portion, a step of forming a pin hole through a joint portion of the shaft divided body, and driving a pin into the pin hole to prevent the shaft divided body from coming off; Polishing the shaft support points so that the plurality of shaft support points on the shaft are substantially concentric.
[0007]
According to such a configuration, after fitting and integrating the convex portions and concave portions formed at the end portions of the plurality of shaft divided bodies, a pin is driven into the joint portion so as to prevent the shaft from falling out, and only the shaft support portion is fixed. By performing the polishing process, a long shift shaft is manufactured. That is, since the shift shaft slides only in the axial direction, even if the coupling between the shaft divided bodies is not performed with high accuracy, the function is as long as the coaxiality of the shaft support portion is secured. It is fully demonstrated. And since the total length of each shaft division body is short, the machining becomes easy and the manufacturing time is shortened. Further, since the shaft divided bodies are prevented from coming off by the pins driven into the joints thereof, they do not easily loosen or separate, and the function as the shift shaft is maintained for many years.
[0008]
The invention according to claim 2 is characterized in that a male screw and a female screw are respectively formed in the convex portion and the concave portion.
According to this configuration, the shaft divided bodies are screwed and integrated with the male screw and the female screw, so that the coupling strength is improved and, for example, the output of the air cylinder is reliably transmitted to the shift fork.
[0009]
According to the third aspect of the present invention, a guide portion is formed at the front end portion of the convex portion and the deep portion of the concave portion so as to make the central axis substantially straight when the shaft divided bodies are fitted and integrated. It is characterized by having.
[0010]
According to such a configuration, when the shaft divided bodies are fitted and integrated, the guide portions formed at the distal end of the convex portion and the deep portion of the concave portion are fitted, and the central axis of the shaft divided body is substantially aligned. Be straight.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a method of manufacturing a shift shaft according to the present invention.
[0012]
As shown in FIG. 1A, the shift shaft 10 is composed of two shaft divided bodies 12 and 14 divided at substantially the center in the axial direction. As shown in FIG. 2, at opposite ends of the shaft divided bodies 12 and 14, that is, at divided parts of the shift shaft 10, one of the convex parts 12 </ b> A having a male screw as a coupling part that can be fitted to each other. Concave portions 14A each having a female screw on the other side are formed. In addition, when the shaft divisions 12 and 14 are fitted and integrated, the tip of the projection 12A and the back of the recess 14A have guide portions 12B that can be fitted to each other so that the center axis is substantially aligned. And 14B are respectively formed.
[0013]
When manufacturing the shift shaft 10 from the two shaft divided bodies 12 and 14, the following steps are sequentially performed.
As a first step, as shown in FIG. 1 (A), the male screw of the convex portion 12A and the female screw of the concave portion 14A are screwed together while the ends of the two shaft divided bodies 12 and 14 face each other. To At this time, the central axes of the integrated shaft divided bodies 12 and 14 are kept substantially straight by fitting the guide parts 12B and 14B formed in the convex part 12A and the concave part 14A, respectively.
[0014]
As a second step, as shown in FIG. 3B, the guide portions 12B and 14B formed in the joint portion of the integrated shaft divided bodies 12 and 14, preferably formed in the convex portion 12A and the concave portion 14A, respectively, are penetrated. In this case, a pin hole 16 perpendicular to the axis is formed to penetrate. Then, various pins 18 such as a solid pin and a spring pin are driven into the pin holes 16 to prevent the shaft divided bodies 12 and 14 from coming off from each other. Here, it is desirable to use a pin 18 having a tightening margin.
[0015]
As a third step, as shown in FIG. 3C, the outer periphery of a portion where the shift shaft 10 is supported, that is, the shaft supporting portions 20A to 20D which are supported by bosses formed in the casing of the transmission. The surfaces are polished so that they are located substantially concentrically.
[0016]
According to such a shift shaft manufacturing method, after the two shaft divided bodies 12 and 14 are screwed together and integrated, the pin 18 is driven into the joint to prevent the shaft divided bodies 12 and 14 from coming off, and only the shaft supporting points 20A to 20D are supported. By performing the polishing process, the long shift shaft 10 can be easily manufactured in a short time. That is, since the shift shaft 10 slides only in the axial direction, the coaxiality of the shaft supporting points 20A to 20D is ensured even if the coupling between the shaft divided bodies 12 and 14 is not performed with high accuracy. If so, its function is fully demonstrated. For this reason, even if the shift shaft 10 is divided, no problem occurs, and since the total length of each of the shaft divided bodies 12 and 14 is short, machining becomes easy, and manufacturability can be improved through shortening of the manufacturing time. . Further, since the manufacturability is improved, the manufacturing cost of the shift shaft can be reduced.
[0017]
Further, since the shaft divided bodies 12 and 14 are prevented from coming off by the pins 18 driven into the joints thereof, for example, when the piston of the air cylinder at the end of the shift shaft 10 is disassembled, the impact is reduced. Even if the nut is loosened using a wrench or the like, the shaft coupling portion is not loosened or separated. Therefore, the function as the shift shaft 10 can be maintained for many years.
[0018]
In the embodiment described above, the male screw and the female screw are formed in the convex portion 12A and the concave portion 14A of the shaft divided bodies 12 and 14, respectively, but have a circular cross-section that also functions as the guide portions 12B and 14B. A columnar portion may be formed. The division of the shift shaft 10 is not limited to two, but may be three or more in accordance with the total length.
[0019]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the entire length of the shaft divided body constituting the shift shaft is short, the machining can be facilitated, and the manufacturability can be improved through shortening of the manufacturing time. it can. Further, since the shaft divided bodies are prevented from falling off by the pins driven into the joints, they do not easily loosen or separate, and can continue to function as the shift shaft for many years. it can.
[0020]
According to the second aspect of the present invention, since the shaft divided bodies are screwed and integrated with the male screw and the female screw, the coupling strength is improved, and for example, the output of the air cylinder is reliably transmitted to the shift fork. Can be transmitted.
[0021]
According to the third aspect of the present invention, when the shaft divided bodies are fitted and integrated, the guide parts formed respectively at the tip of the convex part and the deep part of the concave part are fitted, and the shaft divided body is formed. The central axis is substantially straight. For this reason, it is sufficient to perform the polishing processing of the pivot support portion at the minimum necessary, and the productivity can be further improved.
[Brief description of the drawings]
FIG. 1 shows a method of manufacturing a shift shaft according to the present invention, wherein (A) to (C) are explanatory views of a first step to a third step, respectively. FIG. 3 is an explanatory view showing a transmission mechanism of a multi-stage transmission.
Reference Signs List 10 shift shaft 12 shaft divided body 12A convex part 12B guide part 14 shaft divided body 14A concave part 14B guide part 16 pin hole 18 pin 20A to 20D

Claims (3)

A shift shaft to which a shift operation force is transmitted is divided into a plurality of shafts, and a shaft divided body formed with a convex portion and a concave portion which can be fitted to the facing end is integrated by fitting the convex portion and the concave portion. The process of
A step of forming a pin hole through the joint of the shaft divided body, and driving a pin here to prevent the pin from coming off,
Polishing the shaft support points so that the plurality of shaft support points on the shift shaft are substantially concentric;
Are sequentially performed. The shift shaft manufacturing method according to claim 1, wherein a male screw and a female screw are respectively formed in the convex portion and the concave portion. A guide portion is formed at a distal end portion of the convex portion and a deep portion of the concave portion so that when the shaft divided bodies are fitted and integrated, a central axis thereof is substantially aligned. The shaft manufacturing method according to claim 1 or 2.

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