JP3035152U - Press forming machine - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide a forging machine capable of forging a metal part integrally formed with a large-diameter hollow shaft portion having a large-diameter hole portion in the middle thereof from a tubular material. SOLUTION: When a tubular material A is supplied between a die side die 3 and a punch side die 5, and the punch side die 5 is moved forward, the tubular material A becomes a double die 3,5. Are housed in a cavity formed by facing each other, and the small-diameter hole portion 5a of the punch-side die 5 in the cavity.
When the movable punch 18 plunges into the inside, the elastic member 11 provided at the tip portion of the fixed punch 10 moves into the molds 3, 2.
5 is pressed into the large-diameter holes 3b and 5b provided on the facing surface side, respectively, and the intermediate portion of the tubular material A is placed on the inner surfaces of the large-diameter holes 3b and 5b of the two dies 3 and 5. The diameter is expanded so as to follow.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a pressure molding machine for molding a tubular part, such as a hole tube for a spark plug, in which a large diameter part having a hollow part having a diameter larger than the inner diameter is integrally formed in the middle part of a metal pipe. .

[0002]

[Prior art]

 As shown in FIG. 10, the spark plug hole tube provided in the cylinder head for covering the outer periphery of the spark plug attached to the cylinder head of the engine has a cylindrical tube A1 'at an intermediate portion thereof, as shown in FIG. A large diameter portion A2 'having a hollow portion A3' having a diameter larger than the inner diameter is integrally formed.

When manufacturing a spark plug hole tube having such a shape, conventionally, for example, a multi-stage press forming machine as disclosed in Japanese Utility Model Laid-Open No. 5-9734 is used. Then, the forming material is subjected to forging while sequentially transferred to a plurality of stages of forging stations composed of a plurality of dies and punches, so that the middle of the cylindrical pipe A1 'as shown by the phantom line in FIG. Part, a semi-molded product having a large diameter portion A2 'having a diameter larger than that of the cylindrical pipe A1' is formed, and then the inner surface of the large diameter portion A2 'is cut to form the large diameter shaft portion A2'. A hollow portion A3 'having a diameter larger than the inner diameter of the cylindrical tube A1' is integrally formed on the inner surface of the.

[0004]

[Problems to be solved by the device]

 However, when manufacturing a spark plug hole tube as described above, in addition to the forging process for forming a tubular semi-molded product having a large diameter portion A2 'in the middle part using a forging machine, a cutting machine is used. It is necessary to use a cutting process to form a hollow portion A3 'having a diameter larger than the inner diameter of the cylindrical tube A1' on the inner surface of the large diameter portion A2 'in the above-mentioned semi-molded product, which results in very poor productivity and cost reduction. But there was a costly problem.

Accordingly, the present invention proposes a forging molding machine capable of forging a tubular part in which a large diameter portion having a hollow portion having a diameter larger than the inner diameter of the tubular material is integrally formed in the middle portion thereof. The task is to serve.

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is characterized by using the following means.

First, a device according to claim 1 of the present application (hereinafter, referred to as a first device) is a die-side mold, a punch-side mold that faces and separates from the mold, and these molds. A large diameter part having a hollow part larger than the inner diameter of the material was integrally formed in the middle part by forging a tubular material with a movable punch that protrudes into the cavity formed by the mold. As a press forming machine for forming tubular parts, the die-side mold is composed of a small-diameter hole part formed in the inner part of the die-side part and a large-diameter hole part formed in the front part and continuous with the small-diameter hole part. And a fixed punch that protrudes into the small-diameter hole from the back of the mold hole and allows the material to be inserted, and the die on the punch side allows the material to be inserted. The hole and the die hole can be inserted into the die hole from the back side and inserted into the material. The movable punch can be inserted into the material at the tip of either the fixed punch or the movable punch, and the movable punch can be inserted between the punch side die and the die side die. An elastic member that is pressed into the large-diameter hole while being compressed into the large-diameter hole to push the intermediate part of the material to expand along the inner surface of the large-diameter hole after the contact. It is characterized by being provided.

Further, a device according to claim 2 (hereinafter referred to as a second device) is characterized in that, in the first device, the elastic member is formed of polyurethane.

Further, a device according to claim 3 (hereinafter, referred to as a third device) is characterized in that, in the first device, the elastic member is constituted by a coil spring.

With such a configuration, in any of the first to third inventions, the tubular material is supplied between the die side die and the punch side die to advance the punch side die. At this time, the material is housed in a cavity formed by the two dies facing each other, and the movable punch projects into the die cavity of the punch-side die in the cavity, thereby fixing the fixed punch. Alternatively, an elastic member provided at the tip of either one of the movable punches is pressed into the large diameter hole while being compressed, and the intermediate portion of the material is expanded so as to extend along the inner surface of the large diameter hole. Will be diameter. As a result, a tubular component having a large diameter portion having a hollow portion having a diameter larger than the inner diameter of the material is formed in the middle portion.

After that, when the punch-side mold is retracted, the elastic member is restored to a shape that can be inserted into the tubular material by its elastic restoring force.

According to the second invention, since the elastic member is made of polyurethane, when the elastic member is pushed into the large diameter hole portion while being compressed by the movable punch, the elastic member is It is possible to expand the diameter so as to accurately follow the inner surface of the large diameter hole portion, whereby the intermediate portion of the material is formed into a shape that accurately follows the inner surface of the large diameter hole portion.

According to the third aspect of the invention, since the elastic member is constituted by the coil spring, when the coil spring is pushed into the large diameter hole portion by the movable punch without being compressed, the coil spring is pressed. The spring is compressed while being prevented from rotating due to the frictional resistance caused by the pushing, and is pushed while expanding the diameter in the large diameter hole. As a result, a tubular part is formed in which the middle part of the material is expanded in diameter along the inner surface of the large-diameter hole and a large-diameter part having a hollow part having a diameter larger than the inner diameter of the material is formed in the middle part. It will be molded.

[0014]

[Embodiment of the invention]

 Hereinafter, embodiments of the present invention will be described.

As shown in FIG. 1, in the forging machine 1 according to this embodiment, a large diameter portion having a hollow portion having a diameter larger than the inner diameter of the raw material is formed in a middle portion of the tubular raw material. A closed-type forging machine for forming a hole pipe for a spark plug, in which a die side die 3 is provided on a die block 2 fixed to a machine base (not shown), and the die side die A punch side die 5 is attached to a ram 4 that reciprocates so as to move toward and away from the die 3 so as to face the die side die 3.

Then, a tubular material A as shown in FIG. 2 obtained by cutting a metal pipe such as a relatively soft iron pipe into a predetermined length is used, and the material A is used for the die side metal of the forging machine 1 of the present invention. By supplying between the die 3 and the punch-side die 5 for forging, a large diameter having a hollow portion B2 larger than the inner diameter of the cylindrical tube B1 in the middle portion of the cylindrical tube B1 as shown in FIG. The portion B3 is formed into an integrally formed spark plug hole tube B. Although not shown in FIG. 4, the above-described forging machine 1 is used as a multi-stage forging machine, and the spark plug hole tube B is further subjected to a finishing process by a forging process similar to that described above in a subsequent step. The hole pipe C for spark plugs, which has been subjected to the above-mentioned steps and further adjusted the shapes of the large-diameter portion B3 and the hollow portion B2 to improve accuracy.

Next, the configurations of the die side die 3 and the punch side die 5 and the mounting structure thereof, which are the characteristic parts of the present invention, will be described respectively.

First, as shown in FIG. 1, in the die block 3, a pressure receiving member 6 that receives a load from the front (punch side, the same applies below), a support member 7, and a die holder 8 are fitted and fixed. ing. The die side mold 3 is fitted and fixed in the die holder 8 with the rear end thereof being held by the support member 7. The die-side mold 3 is arranged in the inner part of the die 3 and has a small-diameter hole portion 3a which allows the material A to be inserted, and a large-diameter hole portion 3b which is arranged in the front part and is continuous with the punch side of the small-diameter hole portion 3a. A mold cavity portion 3A composed of is formed. In addition, a sleeve 9 that penetrates from the rear end surface to the front end surface of the die-side mold 3 is slidably fitted in the support member 7 in the front-rear direction. A fixed punch 10 having a large diameter portion at the rear end thereof sandwiched and fixed between the support member 7 and the pressure receiving member 6 is inserted. The die-side cavity 3A of the die-side die 3, the front portion of the fixed punch 10 and the front end surface of the sleeve 9 form a die-side cavity.

Then, when the movable punch described later, which can be inserted into the material A and is pressed into the die while being compressed in the die side, is compressed in the large diameter hole 3 b side in the front end of the fixed punch 10. While being pushed in, an elastically deformable elastic member 11 is provided which expands the intermediate portion of the material A along the inner surface of the large diameter hole portion 3b. This elastic member 11 is made of urethane as a material and is formed in a bottomed cylindrical shape having the same diameter as or slightly smaller than the inner diameter of the material, and is fixed to the front end surface of the fixed punch 10 by a mounting bolt 12.

Further, the rear end surface of the sleeve 9 is in contact with the front end portions of knockout pin pins 13 ... 13 slidably supported by the support member 7 and the pressure receiving member 6 in the front and rear directions. It should be noted that knockout pin driving means (not shown) for driving the knockout pins 13 ... 13 in synchronization with the forward / backward movement of the ram 4 is provided on the rear end side of the knockout pins 13 ...

Next, the structure on the punch side will be described. A support member 14 is fixed to the ram 4, and a pressure receiving member 15 for receiving a load from the front (die side, the same applies hereinafter) is provided in the support member 14. In addition to being fitted and fixed, a punch case 16 is fixed to the front end of the support member 14, and a cylindrical punch side die 5 is slidable back and forth in the punch case 16. It is installed.

The punch-side die 5 is arranged in the inner portion of the punch die 5 to allow the material A to be inserted therein, and the small-diameter hole portion 5a having an inner diameter and the front portion to be arranged in the large-diameter hole portion 5a. A mold cavity 5A composed of the cavity 5b is formed.

A sleeve 17 penetrating from the rear end surface to the front end surface of the punch-side mold 5 is slidably fitted in the punch case 16 in the front-rear direction. The movable punch 18 having the large diameter portion at the rear end thereof sandwiched and fixed between the support member 14 and the pressure receiving member 15 is inserted. The die cavity 5A of the punch die 5, the front portion of the movable punch 18, and the front end surface of the sleeve 17 constitute a punch side cavity.

Further, the punch side die 5 has a tip portion protruding from the movable punch 18 by a predetermined amount by a spring 19 ... 19 which is mounted between the punch side die 5 and the ram 4 and which penetrates the support member 14. Is biased forward.

Further, the rear end surface of the sleeve 17 is in contact with the front end portions of the knockout pins 20 ... 20 slidably supported by the support member 14 and the pressure receiving member 15 in the front-rear direction. Note that knockout pin driving means (not shown) for driving the knockout pins 20 ... 20 in synchronization with the forward / backward movement of the ram 4 is provided on the rear end side of the knockout pins 20.

Next, the operation of this forging machine will be described.

When the tubular material A cut into a predetermined length as shown in FIG. 2 is appropriately supplied to the forging machine by the material transferring means, as shown in FIG. The die 5 moves forward, one end of the material A enters into the die hole 5A of the punch side die 5, and the one end of the die 5 is moved to the inner surface of the small diameter hole 5a of the die 5A and the outer peripheral surface of the movable punch 18. It will be pushed to the die side while being held between the two.

As a result of this pushing, the other end of the material A is inserted into the die hole 3A of the die die 3 as shown in FIG. 5, and the outer peripheral surface of the elastic member 11 and the fixed punch 10 is Will be fitted to.

Further, a cavity is formed by the punch side die 5 being in contact with the die side die 3, and the material A is accommodated in the cavity, while the movable punch 18 is further provided with a spring 19 ... While compressing 19, it moves forward relative to the punch side die.

Then, the movable punch 18 projects into the small-diameter hole portion 5a of the punch side die 5 in the cavity, so that the elastic member provided at the front end portion of the fixed punch 10 as shown in FIG. 11 is pressed into the large-diameter holes 3b and 5b of both molds 3 and 5 while being compressed, and the elastic member 11 causes the intermediate portion of the material A to be large-diameter holes of both molds 3 and 5. The diameter is expanded along the inner surfaces of 3b and 5b. As a result, the spark plug hole tube B having the large diameter portion B3 having the hollow portion B2 having a diameter larger than the inner diameter of the material is formed in the middle portion.

When the spark plug hole tube B is formed in this way, as shown in FIG. 7, the punch side die 5 is separated from the die side die 3 by the retreat of the ram 4. At this time, a knockout pin driving device (not shown) causes the knockout pin 20 ... 20 on the punch side to move forward relative to the punch-side die 5 to move the sleeve 17 to the die side, and the pipe spark plug hole pipe B It is designed to be pushed to the punch side so that it does not come out together with the movable punch 18. Further, as the movable punch 18 retreats, the elastic member 11 is restored to the bottomed tubular shape that can be inserted into the tubular material A by its elastic restoring force.

Then, the knockout pin driving device on the die side pushes the knockout pins 13 ... 13 toward the punch side, so that the spark plug hole tube B 1 is taken out from the die side die 3.

Although not shown in the drawings, the spark plug hole pipe B molded as described above is subjected to a finishing process by a forging process similar to the above forging process, if necessary, in a post process. Thus, the shape of the hollow shaft portion B3 of the spark plug hole tube B is adjusted more accurately and the accuracy is improved to form a high-precision spark plug hole tube C.

8 and 9 show another embodiment of the elastic member 11, in which a coil spring 11 'is used instead of the elastic member 11 made of urethane.

That is, a coil spring 11 ′ having the same diameter as or slightly smaller than the inner diameter of the material is used, and a small-diameter annular portion 11a ′ is formed at the end of the coil spring 11 ′ on the die side. It is fixed to the front end surface of the fixed punch 10 by a mounting bolt 12 penetrating therethrough.

Other configurations are the same as those in the previous embodiment as illustrated with the same reference numerals.

Even in the case of such a configuration, as in the previous embodiment, the punch-side mold 5 advances, and one end of the material A enters the mold hole 5A of the punch-side mold 5, The one end portion of the die hole portion 5A is pressed into the die while being compressed while being held between the inner surface of the small diameter hole portion 5a and the outer peripheral surface of the movable punch 18.

As a result of this pushing, the other end of the material A is inserted into the die hole 3A of the die die 3 as shown in FIG. 8, and the coil spring 11 'and the fixed punch 10 are separated from each other. It will be fitted on the outer peripheral surface.

A cavity is formed by the punch side die 5 being in contact with the die side die 3, and the material A is accommodated in the cavity, and then the movable punch 18 is further connected to the ram 4. The springs 19 ... 19 between the punch side die 5 and the punch side die 5 are compressed while the springs 19 are moved forward relative to the punch side die 5.

Then, the movable punch 18 projects into the small-diameter hole portion 5a of the punch-side die 5 in the cavity, so that the coil spring provided at the front end portion of the fixed punch 10 as shown in FIG. The frictional resistance 11 ′ causes the frictional force to prevent the rotation of the mold 11 ′, and the compression force 11 ′ is expanded and the diameter of the mold 11 ′ is pushed into the large diameter holes 3 b and 5 b of the molds 3 and 5. As a result, the intermediate portion of the material A is expanded so as to follow the inner surfaces of the large-diameter holes 3b and 5b of the above-mentioned molds 3 and 5, and the hollow portion having a diameter larger than the inner diameter of the material A is provided in the intermediate portion. The spark plug hole pipe B in which the large-diameter portion B3 having the portion B2 is formed is formed.

As described above, when the coil spring 11 'is used as the elastic member, it has excellent durability and can be used for a long period of time.

In the above embodiment, the coil spring 11 ′ has a circular cross section, but a coil spring having a wide pressing area such as a quadrangular cross section may be used.

Further, in each of the above-described embodiments, the large diameter holes 3b and 5b are provided in both of the molds 3 and 5, but they may be provided only in the die side mold 3. Even with this structure, the spark plug hole tube B can be formed in which the large diameter portion B3 having the hollow portion B2 having a diameter larger than the inner diameter of the material A is formed in the middle portion.

The shape of the large-diameter holes 3b and 5b is not limited to a simple cylindrical shape. For example, a multi-stage shape or a semi-spindle shape in which the diameter gradually increases toward the contact surface of each die 3,5. Of course, it may be such.

[0045]

[Effect of the invention]

 As described above, according to the present invention, in any of the first to third inventions, the tubular material is supplied between the die side die and the punch side die to advance the punch side die. At this time, the material is contained in a cavity formed by the two molds contacting each other, and the movable punch projects into the small-diameter hole portion of the punch-side mold in the cavity. An elastic member provided at the tip of one of the fixed punch and the movable punch is pressed into the large-diameter hole side of the die-side die while being compressed, and the intermediate portion of the material is placed on both sides. The diameter is expanded so that it follows the inner surface of the large-diameter hole of the die or the large-diameter hole of the die. As a result, it becomes possible to mold a tubular part in which a large diameter portion having a hollow portion having a diameter larger than the inner diameter of the material is formed in the middle portion.

After that, when the punch side mold is retracted, the elastic swelling member is restored to a shape that can be inserted into the tubular material by its elastic restoring force.

According to the second aspect of the invention, since the elastic member is made of polyurethane, when the elastic member is pushed into the large diameter hole portion while being compressed by the movable punch, the elastic member is It is possible to expand the diameter so as to accurately follow the inner surface of the large diameter hole portion, whereby the intermediate portion of the material is formed into a shape that accurately follows the inner surface of the large diameter hole portion.

Further, according to the third aspect, in addition to the effect of the first aspect, since the elastic member is constituted by the coil spring, it has excellent durability and can be used for a long period of time.

[Brief description of the drawings]

FIG. 1 is a partially omitted cross-sectional view of a press forming machine according to an embodiment of the present invention.

FIG. 2 is a diagram showing a shape of a material processed by the same press forming machine.

FIG. 3 is a view showing a shape of an intermediate material processed by the same press forming machine.

FIG. 4 is a diagram showing a shape of a final product obtained by the same pressure molding machine.

FIG. 5 is an enlarged cross-sectional view showing a state in the middle of the forward movement of the punch side die.

FIG. 6 is an enlarged cross-sectional view showing a state at the end of the advance of the punch side die.

FIG. 7 is an enlarged cross-sectional view showing a state in which the punch side die is retracted.

FIG. 8 is a cross-sectional view of a main part showing another embodiment of the elastic swelling member.

FIG. 9 is an enlarged cross-sectional view showing a state at the end of the advance of the punch side die.

FIG. 10 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 3 Die side mold 3A Mold hole 3a Small diameter hole 3 Large diameter hole 5 Punch side mold 5A Mold hole 5a Small diameter hole 5b Large diameter hole 10 Fixed punch 11, 11 'Elastic member 18 Movable punch

Claims (3)

[Utility model registration claims] 1. A tubular material comprising a die-side die, a punch-side die that is opposed to and separated from the die, and a movable punch that projects into a cavity formed by these dies. Is a forging machine for forming a tubular part integrally formed with a large diameter part having a hollow part having a diameter larger than the inner diameter of the material by forging the intermediate part, wherein the die side mold is And a small diameter hole formed in the inner part of the mold for allowing the insertion of the material and a large diameter hole part formed in the front part and continuous with the small diameter hole part, and a small diameter part from the inner part of the mold hole part. The punch side die has a fixed punch that projects into the hole and allows the material to be inserted, and the punch side die has a die hole that allows the material to be inserted and the die from the back side of the die hole. It has a movable punch that can be moved into the hole and inserted into the material. The movable punch can be inserted into the tip of one of the moving punches, and the movable punch protrudes into the die hole of the punch side die after the punch side die and the die side die are brought into contact with each other. At this time, the press forming machine is provided with an elastic member that is pressed into the large diameter hole while being compressed to expand the intermediate portion of the material so as to extend along the inner surface of the large diameter hole. 2. The press molding machine according to claim 1, wherein the elastic member is made of polyurethane. 3. The press forming machine according to claim 1, wherein the elastic member is a coil spring.