JPS63248532A - Thread rolling flat die - Google Patents

Abstract

PURPOSE:To enable the good accuracy rolling of a helical gear of odd number teeth, helical flute, etc., by arranging a 1st tooth and 1st tooth space at symmetrical position to the shaft center of a rolling gear. CONSTITUTION:The finishing tooth group 2 of a rack 1 of one part is composed of the 1st tooth 3 having a nomal tooth thickness over the range of at least two times the number of teeth of a rolling gear and the 2nd tooth 4 escaping its both tooth faces by thinning the tooth thickness. A 1st tooth is intermittently arranged one by one on each arrangement of a 2nd tooth 4. The finishing tooth group 6 of the rack 5 of the other part is equipped with the 1st tooth space 7 in a normal space width over the range at least two times the number of teeth of the rolling gear and the 2nd tooth space 8 escaping both tooth faces opposing to both sides by enlarging the space width and the 1st tooth space 7 is arranged by one place each at one place on each arrangement of the 2nd tooth space 8. Also, in the meshed state of these teeth 1, 5 and rolling gear 9 the 1st tooth 3 and 1st tooth space are made at symmetrical position to the shaft center O of the rolling gear.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a flat die for rolling helical gears, oil grooves, and other helical teeth or grooves by sandwiching and moving the object to be rolled, and particularly for forming an odd number of teeth or grooves. This is about flat dies that are effective in this case.

[Prior art and its problems]

For example, as a method for manufacturing the helical gear G shown in Fig. 4, cutting with a bob cutter or the like or rolling may be considered, but the cutting method takes a long time and requires cutting with a hob. Since unnecessary portions due to scraping are required, it is necessary to prepare a workpiece larger than the final product, and there are problems such as higher tool costs. On the other hand, with the method of rolling, the above-mentioned problems do not occur, but since it is a method that applies a large load to the object to be rolled and causes it to plastically deform, conventional methods cannot achieve sufficient accuracy. Helical gear G is created by cutting.
The reality is that they are manufacturing. That is, when manufacturing the helical gear G by rolling, the object to be rolled 9' is inserted into a pair of flat dies 1 as shown in FIG.
This is done by clamping the rolled material by ``, 5'' and applying a load P, and in this state, moving each flat die 1°, 5° in relatively opposite directions to rotate the rolled product 9°.
Especially for helical gears G with odd number of teeth, the rolled object should be 9°
Since the number of teeth meshing with the flat die 1', 5° changes, a tooth misalignment error occurs. FIG. 6 is a diagram for explaining the movement of the meshing points, and when the rolled object 9° is at the position shown by A with respect to the flat die 1°, the two points are 81 points, 82 points, and 83 points. When the rolled object 9° moves relatively to the position shown by B in Fig. 3, the two will move to point b1,
They mesh at a total of four points, b2 points, b3 points, and b4 points, and on the other hand, the other flat die 5' and the rolled object 9° are opposite to the case shown in Fig. 3. When it is in the position not shown by A, it meshes at 4 points, and when it is in the position shown by B, it meshes at 3 points. When rolling a helical gear G with an odd number of teeth in this way, the number of meshing teeth and the meshing point change, and the meshing teeth on one flat die 1' side and the other flat die 5' side change. Due to the difference in number and engagement point position, the flat die I°, 5"
The amount of push into the rolled object at 9° changes. As a result, the load acting on the rolled object 9° changes, and the rolled object 9'
is displaced or deformed even slightly in the direction shown by the arrow in FIG. It becomes undulating at the same pitch as Pa. Such an error e will not occur if the 9° displacement or deformation of the rolled object can be prevented, but in order to completely prevent the 9° displacement or deformation of the rolled object, the rolled object 9'' must be a rigid body. In reality, such a thing is impossible.As described above, conventionally, the tooth trace error is large when rolling is performed, so it is difficult to roll helical gears etc. with a precision that can be used in practical use. As a result, in many cases helical gears and the like are manufactured by cutting.

[Purpose of the invention]

The present invention has been devised in view of the above problems and to effectively solve them. Therefore, the object is to provide a flat rolling die that can accurately roll helical gears with odd number teeth, helical grooves, etc.

[Means to solve the problem]

The flat rolling die according to the present invention has the following configuration in order to solve the problems of the prior art and achieve the objectives. In other words, a group of biting teeth consisting of a plurality of biting teeth with increasing tooth height, followed by a group of finishing teeth.
A rolling die is made of a pair of racks, each of which has a group of barbed teeth and is arranged opposite to each other with the object to be rolled in between. The first tooth is composed of a first tooth that has a normal tooth thickness over a range of at least 2n times, and a second tooth that has a thinner tooth thickness and has both tooth surfaces escaped, and the first tooth is Each time (2n-1) of the second teeth are arranged, one tooth is intermittently arranged. The second tooth group of the other rack has a first tooth groove having a normal groove width over a range of at least 2n times the number of teeth of the gear to be rolled, and a first tooth groove having a regular groove width over a range of at least 2n times the number of teeth of the gear to be rolled, and a second tooth groove formed by leaving both tooth surfaces facing on both sides, and the first
The tooth grooves are intermittently arranged at one position each time the second tooth groove is arranged at (2n-1) positions. Further, the first tooth and the first tooth groove are arranged at symmetrical positions with respect to the axis of the rolled gear. However, n represents a positive integer and is usually I or 2. Note that the finished tooth group formed by the second tooth and the second tooth groove may be formed over the entire area of the finished tooth group, and the number of teeth of the rolled gear may be increased. It may be configured only in a range of 2n times or more.

[Effect]

The flat rolling die according to the present invention works as follows to solve the problems of the prior art and achieve the objectives. That is, the first tooth of one rack and the first tooth groove of the other rack, and the second tooth of one rack and the second tooth groove of the other rack are connected to each other on the rolled gear. They always mesh simultaneously with the rolled gear at symmetrical positions with respect to the axis. A rolling load is applied only when the first tooth and the first tooth groove are meshed with the gear to be rolled, and the second tooth and the second tooth groove in which relief is formed are applied to the gear to be rolled. In a bitten state,
The teeth and tooth grooves are in a non-contact state with the teeth of the gear to be rolled, so that no rolling load is applied. Therefore, the rack of the present invention has a number of months/n of first teeth and first tooth grooves compared to a conventional rack that is formed entirely of first teeth and first tooth grooves. Therefore, the rolling load is reduced to I/n accordingly. Furthermore, when rolling a helical gear with an odd number of teeth, the number of meshing teeth and the meshing point change, and the number of meshing teeth and the meshing point position are different between one die side and the other die side. By making the second teeth and second tooth grooves mesh with the rolled gear in a non-contact manner, the load acting on the rolled gear can be placed at a position approximately symmetrical with respect to the axis of the rolled gear. to prevent displacement and deformation of the rolled gear. The ratio of the first tooth is 1 for every 20, so
The area where such relief teeth and relief tooth grooves are provided needs to be formed over a range that is at least 2n times the number of teeth of the gear to be rolled, and by this, the gold teeth of the gear to be rolled can be finished uniformly. be able to.

【Effect of the invention】

As is clear from the above description, the present invention provides the following excellent effects. That is, helical gears with odd number teeth, helical grooves, etc. can be rolled with high precision.

【Example】

A preferred embodiment of the present invention will be described below with reference to FIGS. 1 to 3.
This will be explained with reference to the figures. FIG. 1 shows a flat rolling die according to the present invention with n=1
FIG. 2 is a perspective view showing an example of a finished tooth group consisting of a first tooth and a second tooth in the case of 1. FIG. FIG. 3 is a perspective view showing a group of finished teeth of the other rack in a pair. In each figure, the dashed-dotted line indicates the tooth surface when no relief is formed. The finishing tooth group 2 of one rack 1 is
Consisting of a first tooth 3 having a normal tooth thickness over a range at least twice the number of teeth of the rolled gear, and a second tooth 4 having a thinner tooth thickness so that both tooth surfaces are free. In addition, the first teeth 3 are arranged intermittently one by one every time one second tooth 4 is arranged. That is, when n=1, the first teeth 3 and the second teeth 4 are arranged alternately. The finishing tooth group 6 of the other rack 5 has a first groove having a regular groove width over a range at least twice the number of teeth of the gear to be rolled.
The first tooth groove 7 has a second tooth groove 7 at one location, and a second tooth groove 8 formed by increasing the width of the groove so that both tooth surfaces facing on both sides are released. Each groove 8 is arranged intermittently at one location. That is, when n=1, the first tooth grooves 7 and the second tooth grooves 8 are arranged alternately. Furthermore, when the racks 1 and 5 are in mesh with the rolled gear 9, as shown in FIG. It is arranged in a symmetrical position with respect to 0.

[Brief explanation of drawings]

FIG. 1 shows a flat rolling die according to the present invention with n=1
FIG. 2 is a perspective view showing an example of a double tooth group consisting of a first tooth and a second tooth in the case of the present invention. FIG. 3 is a perspective view showing the finishing tooth group of the other rack that is not paired with the tooth group, and FIG. FIG. 4 is a front view showing an example of a helical gear, FIG. 5 is a simplified front view for explaining the rolling method of helical gears, and FIG. 6 is a diagram showing a material to be rolled and a flat die. FIG. 7 is an explanatory diagram for explaining changes in the number of meshing teeth and the meshing point, and FIG. 7 is a schematic diagram of waviness occurring on the tooth surface of the rolled product. l... One rack, 2... Its finishing tooth group, 3...
...First tooth, 4...Second tooth, tail...Other rack, 6...Group of finished teeth, 7...First tooth groove, tail...
・Second tooth groove, 9... Rolled gear, O... The meticulous patent applicant Toyota Motor Corporation (and one other person)

Claims (1)

[Claims] (1), a finishing tooth group (2, 6) consisting of a plurality of finishing teeth is formed following a biting tooth group consisting of a plurality of biting teeth with increasing tooth heights, and sandwiching the rolled gear (9). The rolling die consists of a pair of racks (1, 5) facing each other, and the finishing teeth group (2) of one rack (1) are the teeth of the gear to be rolled (9). Consisting of a first tooth (3) having a normal tooth thickness over a range of at least 2n times the number, and a second tooth (4) having a thinner tooth thickness and having both tooth surfaces freed, and the first tooth (3) has (2n-1) said second teeth.
The finishing tooth group (6) of the other rack (5) has at least 2n times the number of teeth of the rolled gear (9). A first tooth groove (7) having a regular groove width over a range, and a second tooth groove (8) formed by increasing the groove width and allowing both tooth surfaces facing on both sides of the groove to escape. , and the first tooth groove (7) is arranged intermittently at one position each time the second tooth groove (8) is arranged at (2n-1) positions, and the first tooth groove (3) and the first tooth groove (7) are arranged at symmetrical positions with respect to the axis (0) of the gear to be rolled (9). However, the above n represents a positive integer.