JPH0450090B2 - - Google Patents

Description

Detailed Description of the Invention (a) Technical Field of the Invention The present invention relates to a combination of a hollow member and a member having a mounting hole, such as a transmission, a camshaft, etc. This invention relates to a combined body formed by connecting a member and a hollow member by expanding the tube.

(b) Conventional technology and problems In general, camshafts for internal combustion engines are subject to a lot of wear because the cam part slides in impactful contact with the rocker arm and tappet. Camshafts are often used.

However, the Young's modulus of cast iron is 10,000 to 12,000.
Because of the low Kg/mm ² , cast iron camshafts must have thicker shafts to increase rigidity, which has the disadvantage of being heavy. Furthermore, the cast iron camshaft is chilled by applying a chiller to the cam sliding surface.
In addition to variations in quality, there is a problem of high wear under harsh operating conditions, such as diesel engines where the oil is contaminated with carbon particles and engines using leaded gasoline where the oil is contaminated with lead compounds.

Conventionally, there has been a method of brazing other parts to the steel pipe (Japanese Patent Application Laid-open No. 86456/1989) as a method to reduce the weight and improve the wear resistance of the cam part as described above.
In this method, the steel members of the camshaft and the support jig made of refractory material are placed in a high-temperature atmospheric furnace and brazed, resulting in large equipment and problems in terms of workability and economy.

In addition, in order to accurately produce a phase difference between the cams, there is a method of providing a groove on the cam shaft and a corresponding protrusion on the cam piece, and brazing the joint between the two (Japanese Patent Laid-Open No. 54-41266). However, this method also uses brazing to connect the cam piece and camshaft, and it cannot be heated at 1120℃.
The brazing metal (copper) melts and penetrates in a protective atmosphere for 30 minutes to form a metallurgical bond. Therefore, it has the same drawbacks as the above-mentioned Japanese Patent Application Laid-Open No. 54-86456. However, in the camshaft constructed by this method, only the grooves and protrusions of the cam piece and the camshaft are in contact with each other, so there is a problem in ensuring torque transmission.

Furthermore, a method has been proposed in which a serration or spline is provided on the inner circumferential surface of the through hole of the cam piece, a camshaft is placed in the through hole, and then the pipe that is to become the camshaft is expanded and the two are connected. In this case, the meat of the camshaft is not sufficiently spread through the serrations or the spline during tube expansion, and this structure cannot naturally be applied to items such as counter gears that require larger torque transmission than the camshaft.

(c) Purpose of the invention Therefore, the present invention provides a combination of a member having a mounting hole and a hollow member, which is applicable to applications where desired torque transmission is required, such as transmissions, camshafts, etc. With the goal.

(d) Structure of the Invention In order to achieve the above object, the present invention includes a member having a mounting hole and a plurality of grooves or protrusions having sloped sides on the inner peripheral surface of the mounting hole; The outer peripheral surface has a plurality of protrusions or grooves that are symmetrical with the plurality of grooves or protrusions provided with the member and are smaller than the plurality of grooves or protrusions, and the plurality of protrusions or grooves are provided. a hollow member whose outer circumferential surface has a smaller diameter than the inner circumferential surface of the member, and the hollow member penetrates the member having the mounting hole and is expanded to pass through the grooves and protrusions of both through the slope. They are joined by being brought into close contact.

In the present invention, when the hollow member is expanded into a member having a mounting hole by penetrating the hollow member and aligning the plurality of grooves and protrusions of both, the material of the hollow member is expanded. The fluid flows between the groove and the protrusion through the slopes of both, and can bring the groove and the protrusion into close contact with each other.

(e) Examples of the invention Examples of the invention will be described below based on the drawings.

FIG. 1 shows an example in which the present invention is applied to a transmission, where 1 is a counter drive gear, 2 is a counter drive gear, and 2 is a counter drive gear.
is 1st speed counter gear, 3 is 2nd speed counter gear, 4 is 3rd speed counter gear, 5 is 5th speed counter gear, 6 is reverse idler gear, 7 is counter shaft, 8 is main drive・Gear, 9 is 1st speed main gear, 10 is 2nd speed main gear
Gears 11 are 3rd speed main gear, 12 are 5th speed main gear, and 13 are main shaft.

Counter drive gear 1, 1st speed counter
Gear 2, 2nd speed counter gear 3, counter gear 4, 5th speed counter gear 5, and reverse idler gear 6 are made of the same materials as those of a normal transmission, for example, as shown in FIGS. 2 and 3. As shown in the figure, it is an annular body with a predetermined gear provided on its outer circumferential surface, and a through hole 14 formed in the center has a groove or protrusion 15 formed on its inner circumferential surface. This groove or protrusion 15 is a spline, serration, etc., and is formed by plastic working, for example, backward extrusion.
The groove or protrusion 15 is formed symmetrically in consideration of balance.

On the other hand, the counter shaft 7 is made of a hollow body, and has a shape on its outer periphery that can be engaged with the grooves or protrusions 15 provided in the through holes of the gears 1 to 6, as shown in FIGS. 2 to 4, for example. The protrusions or grooves 16 are formed by cold forging.

The grooves or protrusions 15 and 16 formed in each of the gears 1 to 6 and the counter shaft 7 have slopes 15a and 16a on both sides thereof inclined at a desired angle, for example, as shown in FIGS. 2 and 3. It is becoming. This is so that when the pipe is expanded, the flesh of the countershaft 7 pushed outward by the pipe expansion comes into close contact with the slope 15a of each gear 1 to 6 via its slope 16a, so that the strength capable of transmitting the desired torque can be exerted. It's summery. These slopes 15a and 16a
It has a nice shape because it can be joined without any play. That is, if the shape of the slopes 15a and 16a is like a dovetail groove, the flow of material during pipe expansion is blocked by the narrow entrance, and only a partially bonded state can be formed. Since the protrusion or groove 16 is formed in the flow direction and the groove or protrusion 15 on the gear side has a corresponding shape, the material of the hollow member is the groove or protrusion 1.
5 and its slope 15a, and can form a reliable bonded body without play.

The gears 1 to 6 and the countershaft 7 constructed in this way are first arranged on the countershaft 7 in a predetermined arrangement and set in any pipe expansion device. At this time, each of the gears 1 to 6 and the counter shaft 7 face each other with a gap in between, as shown in FIG. Next, a predetermined tube expansion operation is performed by applying pressure with a tube expansion punch inside the counter shaft 7, and the flesh of the counter shaft 7 is pushed out in the outer circumferential direction, and as described above, each gear 1 to 6 and the counter The grooves provided in the shaft 7 and the slopes 15a of the protrusions 15, 16, respectively,
16a in close contact with each other, and at the same time connect each gear 1.
By joining the inner circumferential surfaces 14a of 6 to 6 and the outer circumferential surface 7a of the counter shaft 7, the transmission A shown in FIG. 1 is obtained.

In the above embodiment, each gear of the transmission was explained as a member having a mounting hole, but the invention is not limited to this, and any material that requires torque transmission, such as a cam piece of a camshaft, etc. It's okay to be. Further, although the camshaft has been described as a hollow member, the present invention is not limited to this, and any member may be used as long as the member having the above-mentioned attachment hole can be joined by pipe expansion. Furthermore,
Although the case where the protrusions or grooves provided on the hollow member are provided all around the circumference has been described, the present invention is not limited to this, and may be provided only at the portion where the gear is provided, for example, as shown in FIG. Further, the shape of the groove or protrusion is not limited to the substantially trapezoidal cross section as shown in the figure, but may be any shape as long as it has slopes on both sides, such as a substantially triangular cross section.

(C) Effects of the Invention As described above, according to the present invention, a plurality of grooves or protrusions each having sloped sides on both sides are provided at the portion where the member to be expanded and joined and the hollow member are joined, and the groove Alternatively, since the slopes of the protrusions and the inner and outer circumferential surfaces of both members are closely connected by tube expansion, a structure that can transmit the desired torque can be easily and reliably formed, and a tube expansion and connection method that does not use heat can be used. In order to
The working environment during joining is good, and the production equipment requires only a press with low power, so it is excellent in terms of production costs and productivity. In addition, since the grooves or protrusions provided on the member with the mounting hole and the hollow member are both formed by plastic working, they can be processed at a lower cost and more efficiently than machining such as machining, reducing production costs and productivity. Excellent in terms of Furthermore, if grooves or protrusions are provided on the gear side and the shaft side, for example, the phases of the upper and lower gears can be matched, which has the practical benefit of improving torque retention. In addition, for example, in a transmission, the gear side is required to have a desired hardness, so it must be made of a specified material, but the shaft side only needs to be able to transmit torque, so it is lighter than the gear. It also has the advantage that it can be constructed from different types of materials, such as being constructed from inexpensive materials.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a transmission manufactured according to the present invention, FIG. 2 is a sectional view of a combined body according to the present invention, FIG. 3 is a sectional view showing a state before connection, and FIG.
The figure is a perspective view of a hollow body according to the present invention, and FIG. 5 is a perspective view showing a modified example of the hollow body. In the figure, 1 is the counter drive gear, 2
is 1st speed counter gear, 3 is 2nd speed counter gear, 4 is 3rd speed counter gear, 5 is 5th speed counter gear, 6 is reverse idler gear, 7 is counter shaft, 8 is main drive・Gear, 9 is 1st speed main gear, 10 is 2nd speed main gear
11 is a 3-speed main gear, 12 is a 5-speed main gear, 13 is a main shaft, 14 is a through hole, 15 and 16 are grooves or protrusions, and 15a and 16a are slopes, respectively.

Claims (1)

[Scope of Claims] 1. A member having a mounting hole and having a plurality of grooves or ridges provided on the inner peripheral surface of the mounting hole with sloped sides on both sides, and a plurality of grooves or protrusions provided on the outer peripheral surface of the member. It has a plurality of protrusions or grooves that are symmetrical with the grooves or protrusions and smaller than these plurality of grooves or protrusions, and the outer peripheral surface without these plurality of protrusions or grooves is the inner periphery of the member. and a hollow member with a smaller diameter than the surface, the hollow member passing through the member having the attachment hole, and being expanded and connected by bringing the grooves and protrusions of both into close contact via the slope. A combination of a member having a mounting hole and a hollow member. 2. A combination of a hollow member and a member having a mounting hole according to claim 1, wherein the hollow member is provided with a plurality of grooves or protrusions along its entire length. 3. A combined body of a member having a mounting hole and a hollow member according to claim 1, wherein the hollow member is provided with a plurality of grooves or protrusions only at the joint portion with the member having the mounting hole. 4. A combination of a member having a mounting hole and a hollow member according to claim 1, wherein the member having a mounting hole is provided with a gear on its outer periphery. 5. A combination of a member having a mounting hole and a hollow member according to claim 1, wherein the member having a mounting hole and the hollow member are made of different materials.