JPH0390244A - Manufacture of main body fixture - Google Patents

Abstract

PURPOSE:To improve the productivity by forming a first end part whose diameter is smaller than the center part of the body and whose cross section is circular on one side of the body, forming a recessed part in the other end of the body, and forming a second end part of a hexagonal shape on the other side of the body without inverting it. CONSTITUTION:In a first process, a first end part 109 whose diameter is smaller than the center part of the body and whose cross section is circular is brought to extrusion on one side of the body, and also, a recessed part is formed in the other end of said body. Subsequently, from a first process to a prescribed position of a second process, the body formed in a first process is transferred without inverting it. Next, by a second process, a second end part 113 whose diameter is smaller than the center part of its body and whose cross section is hexagonal is brought to extrusion on the other side of the body formed by a first process. In such a way, since the body is transferred without inverting it, a collision of the body and a formwork is prevented, and damage of the body or the formwork can be prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a metal shell, and particularly to a method for manufacturing a metal shell, and in particular, a method for manufacturing a metal shell.
It relates to the manufacturing method of metal shells such as glow plugs, oxygen sensors, water temperature sensors, knock sensors, fuse-type temperature sensors, or thermistor-type temperature sensors.

[Prior Art] Conventionally, for example, in some types of gasoline engines, an ignition plug having a hexagonal metal shell with a smaller diameter above the center of the body is mounted in a recess formed in the cylinder head. ing.

The main metal fitting of a spark plug having such a shape (European Patent No. 0036050) is made by extrusion molding, and has a circular cross section with a smaller diameter than the center of the body on one side of the body.
A first step of forming an end portion, and a second step of forming a second end portion having a hexagonal cross section with a smaller diameter than the center portion of the fuselage on the other side of the fuselage by extrusion molding. The fuselage is manufactured by a manufacturing method that includes a transfer process in which the fuselage is turned upside down and transferred to a second process. Also,
This transfer step has conventionally been carried out using fingers that grasp the body formed by the molding section that performs the first step and move it to the molding section that performs the second step while drawing an arcuate trajectory. It is being said.

[Problem to be Solved by the Invention] However, in the above-mentioned transfer step, when the body is moved by the fingers from the molding section where the first step is performed to the molding section where the second step is performed, the fingers move the body in an arc shape. If the body was turned around while tracing a trajectory, there was a possibility that the body and the molding die would collide, resulting in damage to the body or the molding die.

For example, if the finger moves the body at high speed, the body may be blown outward from the finger due to centrifugal force. For this reason, the transfer speed of the fuselage in this transfer process needs to be slower than the transfer rate of the fuselage in the transfer process in which the fuselage is transferred without inverting it. However, there was a problem in that the productivity of the metal shell was poor.

An object of the present invention is to provide a method for manufacturing a metal shell that can prevent damage to the body or the formwork and improve productivity of the metal shell.

[Means for Solving the Problems] The method for manufacturing a metal shell of the present invention includes the steps of:
A first step of forming a first end portion having a circular cross section and a smaller diameter than the center portion of the body on one side of the body, and forming a recessed portion on the other end of the body, and extrusion molding to form the body. a second step of forming a second end portion having a hexagonal cross section and a smaller diameter than the center portion of the body on the other side;
A technical means is adopted that includes a transfer step of transferring the body formed in the process to the second process without reversing it.

[Function] The method for manufacturing a metal shell of the present invention has the following effects by means of the above-mentioned technical means.

In the first step, a first end portion having a circular cross section and a smaller diameter than the center portion of the fuselage is extruded on one side of the fuselage. At the same time, a recess is formed at the other end of the body. Subsequently, the body formed in the first step is transferred from the first step to a predetermined position in the second step without inverting it. And the second
In this step, a second end portion having a hexagonal cross section and a smaller diameter than the center portion of the body is extruded on the other side of the body formed in the first step.

[Effects of the Invention] The method for manufacturing a metal shell of the present invention achieves the following effects through the technical means and operations described above.

Since the body formed in the first process is transferred to the second process without being turned over, collision between the body and the formwork can be prevented. Therefore, damage to the body or formwork can be prevented.

For example, even if the fuselage is moved at high speed during the transfer process, there is no possibility that the fuselage will be blown outward due to centrifugal force. Therefore, the transfer speed of the fuselage during this transfer process can be increased. Therefore, the productivity of the metal shell can be improved.

[Example 2] A method of manufacturing a metal shell according to the present invention will be explained based on an example shown in FIGS. 1 to 16.

Figures 1 to 15 show the first embodiment of the present invention, Figures 1 to 7 show the molded shape of the body in each molded part, and Figures 8 to 13 show the metal shell for the ignition plug. Each molding section of the cold extrusion molding machine that molds the fuselage according to the manufacturing method shown in FIG.

The cold extrusion molding machine includes first to sixth molding sections 1.2.3.4.5.6 arranged in a straight line and a transfer means 7.

As shown in FIG. It has bunches 12 and kickout pins 13, and is upholstered to form a fuselage W1 (FIG. 1). As shown in FIG. 9, the second preforming part 2 has a mold (die>21, bunches 22, bins 23, and kickout sleeves 24, and is formed by front extrusion molding to form the body W2.
(Fig. 2) is formed. In addition, in this embodiment, centering molding for forming the third rIc-shaped part 3 and subsequent parts is performed by the first restraint-shaped part 1 and the second restraint-shaped part 2.

As shown in FIG. 10, the third molding section 3 is a molding means for performing the first step according to the present invention, and includes a mold (die) 31.
, bunches 32, bunch holders 33, pins 34 and kickout sleeves 35, and undergoes composite (front and rear) extrusion to form fuselage W3 (FIG. 3).

As shown in FIG. 11, the fourth molding section 4 is a molding means for performing the second step according to the present invention, and includes a mold (first die) 41, a bunch (mandrel) 42, and a bunch kickout sleeve. 43, outer sleeve (second die) 44,
It has a pin 45, a pin kickout sleeve 46, and a bin outer sleeve 47, and is hexagonally formed to form the fuselage W4.
(Figs. 4 and 7).

As shown in FIG.
4 and a kick-out sleeve 55, and small hole molding is performed to form a fuselage W5 (FIG. 5).

As shown in FIG. 13, the sixth molding section 6 includes a mold (die).
61, piercing bunch 62, stripper sleeve 6
3. Kickout sleeve 64 and scrap discharge section 65
The body W6 (FIG. 6) is formed by passing through the shaft hole. In this embodiment, the shaft hole is formed by the fifth forming section 5 and the sixth forming section 6.

Each die 11.21.31.51.61 and the outer sleeve 44 are integrally assembled into a fixing member a of the cold extrusion molding machine. Also, each bunch 12.22.3
2.42.52, S2 and die 41 are integrated into a movable member (not shown) of the cold extruder.

As shown in FIGS. 8 to 13, the transfer means 7 includes first to sixth fingers 71 to 78 for gripping the torso, and first to sixth fingers 71 to 78 for gripping the body.
~Third spring 711. 721.731, the fifth spring 751, the sixth spring 761, and the first to
It has first to sixth displacement means (not shown) for displacing the sixth fingers 71 to 76 without inverting them.

The first finger 71 is used to transfer a round bar-shaped body (not shown) cut from steel to the recess of the die 11 of the first r!c-shaped part 1.

The second finger 72 is for transferring the body W1 formed by the first preform part 1 to the recess of the die 21 of the second preform part 2.

The third finger 73 is for transferring the body W2 formed by the second tc-shaped part 2 to the recess of the die 31 of the third tc-shaped part 3.

The fourth finger 74 is a means for performing the transfer process according to the present invention, and is for transferring the body W3 formed by the third TC-shaped part 3 to the recess of the outer sleeve 44 of the fourth TC-shaped part 4. .

The fifth finger 75 is for transferring the body W4 formed by the fourth molding part 4 to the recess of the die 51 of the fifth molding part 5.

The sixth finger 76 is for transferring the body W5 formed in the fifth molding section 5 to the recess of the die 61 of the sixth molding section 6.

A method of manufacturing the metal shell for a spark plug of this embodiment will be explained based on FIGS. 1 to 14.

(B) Round rod-shaped body cut from steel (not shown)
The first finger 71 and the first displacement means
It is transferred to the entrance of the recess of the die 11 of the molding part 1 in a substantially parallel direction without being reversed, and is held at the entrance of the recess of the die 11.

As the movable member of the cold extrusion molding machine moves downward in the figure toward the fixed member a, the bunch 12 press-fits the round rod-shaped body into the recess of the die 11.

The round rod-shaped body press-fitted into the recess of the die 11 has an arc-shaped corner 10 formed by the die 11 in the first preform portion 1.
1 is formed, and centering holes 102 and 103 are formed on the axes of both end surfaces by the tip of the bunch 12 and the tip of the kickout bin 13. Therefore, the first commandment part 1
In the first step, by cold extrusion molding as described above,
The fuselage W1 shown at 55 is formed.

As the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the figure, the bunch 12 moves to the body W1.
move away from At this time, the body W1 is removed from the recess of the die 11 by the kick-out pin 13.

(b) Next, the torso W1 formed by the first precept form part 1
The second finger 72 and the second displacement means
It is transferred from the prescribing section 1 to the entrance of the recess of the die 21 of the second prescribing section 2 in a substantially parallel direction without being reversed, and is held at the entrance of the recess of the die 21.

As the movable member of the cold extrusion molding machine moves downward in the figure toward the fixed member a, the bunch 22 moves to the body W1.
is press-fitted into the recess of the die 21.

The body W1 press-fitted into the recess of the die 21 has a large diameter portion 104 formed by the die 21 in the second molding part 2.
A small-diameter portion 105 is formed, and large centering holes 106 and 107 are formed on the axes of both end surfaces by the tip of the bunch 22 and the tip of the pin 23. Therefore,
In the second TT-shaped portion 2, the body W2 shown in FIG. 2 is formed by cold extrusion as described above.

As the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the figure, the bunch 22 moves to the body W2.
move away from At this time, the body W2 is removed from the recess of the die 21 by the kick-out sleeve 24.

(C) Next, the torso W2 formed by the second precept form part 2
The second finger 73 and the third displacement means
It is transferred from the prescribing section 2 to the entrance of the recess of the die 31 of the third prescribing section 3 in a substantially parallel direction without being reversed, and is held at the entrance of the recess of the die 31.

As the movable member of the cold extrusion molding machine moves downward in the figure toward the fixed member a, the bunch 32 moves to the body W2.
is press-fitted into the recess of the die 31.

In the body W2 press-fitted into the recess of the die 31, a first end portion 109 having a circular cross section and a smaller diameter than the other portion 108 is formed on one side of the body W2 by the die 31 in the third molding portion 3.
is formed. In addition, the tip of the bunch 32 and the e3
4, a concave hole 11G is formed on the axis of both end faces.
, 111 are formed. Therefore, in the third preform part 3, the body W3 shown in FIG. 3 is formed by cold extrusion as described above.

As the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the figure, the bunch 32 moves to the body W3.
move away from At this time, the body W3 is removed from the recess of the die 31 by the kick-out sleeve 35.

(d) Next, the fuselage W3 formed by the third molding section 3
The third finger 74 and the fourth displacement means
The outer sleeve (second die) 44 of the outer sleeve (second die) 44 of the outer sleeve 44 is transferred in a substantially parallel direction from the outer sleeve 3 to the outer sleeve 44 in a substantially parallel direction. The first end 109 is held within the sleeve 47, followed by the other portion 108 within the outer sleeve 44.

By moving the movable member of the cold extrusion molding machine downward in the figure toward the fixed member a, a bunch (mandrel) is formed.
A bunch (mandrel) 42 protruded by a spring (not shown) provided at the upper end of the body W3 is inserted into the hole 110 of the concave portion of the body W3, and the die 41 comes into contact with the end surface of the outer sleeve 44. When moving downward, the outer sleeve 44 is also moved downward in the figure by a spring (not shown) provided at the lower end of the fixing member a, and the upper part of the body W3 is press-fitted into the die 41, and furthermore, the other side is connected to the pin. 45 and pin outer sleeve 4
It is press-fitted by the biasing force 7. Since the fourth finger 74 has escaped as shown in FIG. 11, the movable member descends until the lower end surface of the die 41 in the drawing comes into contact with the upper end surface of the outer sleeve 44.

The body W3 press-fitted into the recess of the die 41 has a die 41 and a bunch (mantle) 42 in the fourth molding part 4.
Thus, the center portion 112 of the fuselage W4 is formed. In addition, a second end portion 113 having a diameter smaller than that of the center portion 112 and a hexagonal cross section is provided on the other side of the fuselage W4, and the second end portion 11
A hole 114 is formed within 3.

Therefore, in the fourth shaped portion 4, the body W4 shown in FIG. 4 is formed by cold extrusion molding as described above.

When the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the drawing, the bunch kickout sleeve 43 is pressed, and the bunch 42 and die 41 are moved to the upper end surface and the second end 113 of the body W4 as shown in the drawing. move away from At this time, the pin kickout sleeve 46 causes the fuselage W4 to
is removed from the recess of the outer sleeve 44.

(E) Next, the fuselage W4 formed by the fourth command part 4
The fourth finger 75 and the fifth displacement means
It is transferred from the prescribing section 4 to the entrance of the recess of the die 51 of the fifth prescribing section 5 in a substantially parallel direction without being reversed, and is held at the entrance of the recess of the die 51.

As the movable member of the cold extrusion molding machine moves downward in the figure toward the fixed member a, the punch 52 moves toward the body W4.
is press-fitted into the recess of the die 51.

In the body W4 press-fitted into the recess of the die 51, a stepped hole 115 is formed inside one side of the body W4 by the punch 52 in the fifth preform portion 5. Therefore, in the fifth precept portion 5, by cold extrusion molding as described above,
A fuselage W5 shown in FIG. 5 is formed.

As the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the figure, the punch 52 moves toward the body W5.
move away from At this time, the body W5 is removed from the recess of the die 51 by the kick-out sleeve 55.

(f) Next, the torso W5 formed by the fifth commandment part 5
The fifth finger 76 and the sixth displacement means
It is transferred from the molding part 5 to the entrance of the recess of the die 61 of the sixth molding part 6 in a substantially parallel direction without being reversed, and is held at the entrance of the recess of the die 61.

As the movable member of the cold extrusion molding machine moves downward in the figure toward the fixed member a, the punch 62 moves toward the body W5.
is press-fitted into the recess of the die 61.

In the body W5 press-fitted into the recess of the die E)1, a shaft hole 116 is formed inside the body W5 by a punch 62 in the sixth molding part 6, passing through the body W5 in the axial direction.

At this time, the discharged scraps are discharged to the outside through the scrap discharge section 65. Therefore, in the sixth molding section 6, the body W6 shown in FIG. 6 is formed by cold extrusion molding as described above.

As the movable member of the cold extrusion molding machine moves away from the fixed member a and moves upward in the figure, the punch 62 moves toward the body W6.
move away from At this time, the body W6 is removed from the recess of the die 61 by the kick-out sleeve 64.

As described above, since the body formed in the previous process is transferred to the subsequent process without being reversed, the vicinity of the end of the body, the die 11.21.31.51.61 and the outer sleeve 44
Since collision with the vicinity of the recess can be prevented, damage to the vicinity of the end of the body or the vicinity of the recess of the die 11, 21, 31, 51, 61 and the outer sleeve 44 can be prevented.

Furthermore, for example, the first step (the die 31 of the third precept part 3)
Even when the fuselage W3 is transferred from the to the second process (the outer sleeve 44 of the fourth command part 4) at high speed, there is no possibility that the fuselage W3 will be blown outward due to centrifugal force. Since the transfer speed of the body W3 in this transfer step can be increased, productivity of the metal shell can be improved.

(G) The fuselage W6 formed by the first process and the second process as described above is as shown in FIG.
A thread 120 is formed on the outer periphery of the end portion 109, and a circular portion 122 having a smaller diameter than the hexagonal portion 121 and a caulking 711123 are formed by cutting the second end portion 113 by C.
The metal shell 100 is manufactured. And this main metal fitting 1
An outer electrode 124 of an arbitrary shape is attached to the tip of 00 by a joining method such as welding.

By integrally assembling the center part 4181, insulator 82, etc. inside the metal shell 100 manufactured by the manufacturing method described above, a cylinder head of a gasoline engine as shown in FIG. A spark plug 8 is manufactured which is attached to a recess formed in an outer wall.

The shape section ie in FIG. 8 is not necessarily necessary, and depending on the case, a manufacturing method using the second shape section in FIG. 9 may be adopted.

FIG. 16 represents a second embodiment of the present invention, and shows a fourth molding section of a cold extrusion molding machine for molding a body by a method of manufacturing a metal shell for a spark plug.

(Identical to the first embodiment - functional objects are given the same numbers) The fourth molding section 9 of the cold extrusion molding machine of this embodiment has a formwork (first die) 91. Punch (mandrel) 92, bunch kickout sleeve 93, outer sleeve (second die) 94,
It has a pin 95, a pin kickout sleeve 96, and a pin outer sleeve 91.

In this embodiment, in addition to the same effect as in the second embodiment, the tip of the pin outer sleeve 97 is inserted into the mold 91 during hexagonal molding. Therefore, the outer peripheral surface of the body W4 does not face the gap 98 between the illustrated lower end surface of the formwork 91 and the illustrated upper end surface of the outer sleeve 94. 113, the body W4 is drawn from the outer periphery of the center portion 112 of the fuselage W4.
A part of the fuselage W4 does not flow into the above-mentioned gap 98, that is, no cracks occur on the outer periphery of the fuselage W4 hexagonally formed by the fourth forming section 9 of the cold extrusion molding machine.

(Modified example) In this example, the hexagonal second end portion was formed on the body in the fourth precept portion, but any molding portion after the third precept portion may have a hexagonal shape on the torso. A second end can be formed.

That is, in this example, the body was formed using a cold extrusion machine in the order of centering, first step, second step, and shaft hole forming. The body may be formed in the order of the shaft hole forming and the second step.The point is that after the first step is formed, the hexagonal second end of the second step is formed after the fifth or sixth forming section. Molding may also be performed.

Further, the cold extrusion molding machine is not limited to the cold extrusion molding machine of this embodiment as long as it is a cold extrusion molding machine that manufactures a metal shell using a manufacturing method that includes a first step and a second step.

In this embodiment, the present invention was adopted as a method for manufacturing a main metal fitting for a spark plug, but the present invention was applied to a first end of a glow plug, an oxygen sensor, a water temperature sensor, a knock sensor, a fuse-type temperature sensor, a thermistor-type temperature sensor, etc. The present invention may be employed in a method of manufacturing a metal shell having a central portion, a central portion, and a second end portion.

[Brief explanation of drawings]

1 to 15 show a first embodiment of the present invention, No. 151! Figures 6 to 6 are cross-sectional views showing the molded shape of the body in each molding section, Figure 7 is a view of the top of Figure 4, and Figures 8 to 13 are sectional views showing the molded shape of the body in each molding part. FIG. 2 is a cross-sectional view showing each molding section of a cold extrusion molding machine. Fig. 14 is a half-sectional view showing the main metal fitting for the ignition plug;
FIG. 5 is a half sectional view showing the ignition plug. FIG. 16 represents a second embodiment of the present invention, and is a sectional view showing a fourth molding section of a cold extrusion molding machine for molding a body by a method of manufacturing a metal shell for a spark plug. In the figure: 1...First molding part 2...Second molding part 3...Third molding part (molding part that performs the first step) 4.9...Fourth molding part (the molding part that performs the first step) 5...Fifth molding part 6...Sixth molding part 7...Transporting means 8...
Ignition plug 74...Fourth finger (means for performing the transfer process) 100...Ignition plug main metal fitting 109...First end 113...Second end Wl, W2, W3
, W4, W5, W6...fuselage

Claims (1)

[Scope of Claims] 1) (a) By extrusion molding, a first end portion having a circular cross section and a diameter smaller than the center portion of the body is formed on one side of the body, and a recess is formed on the other end of the body. The first to form
(b) a second step of forming, by extrusion, on the other side of the body a second end portion having a hexagonal cross section and a smaller diameter than the center portion of the body; (c) in the first step; A method for manufacturing a metal shell, comprising: a transfer step of transferring the formed body to the second step without reversing it.