JP2571997B2 - Manufacturing method of handle and hook for truck carrier lifting latch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a handle and a hook used for latching a truck bed.

[0002]

2. Description of the Related Art As a latch for stopping the swing of a truck bed, for example, the one shown in FIG. 10 has been used. That is, by welding the back of the U-shaped support piece 1 to the frame of the carrier, the two support pieces 1 are attached to the frame in parallel and perpendicularly. The vicinity of the upper end of the handle A is inserted between the support pieces 1, and the handle A is attached to the support piece 1 with the pins 2 so that the handle A can rotate. The lower part of the handle A is a grip portion a, and the grip portion a
The vinyl cover 3 is folded from below and fitted from below. At a position slightly below the upper end of the handle A, the vicinity of the lower end of the jaw 4 bent in a U-shape is
It is attached by. The lower end of the jaw 4 is bent inward to form a stopper 6. A vertical slit 7 is formed in the middle of the right and left of the jaw 4, and both ends of the sliding plate 8 pass through the slit 7. Further, holes are formed in the upper portion of the jaw 4 and the center of the sliding plate 8, respectively, and a rectangular bar-shaped portion below the hook C is inserted into the holes from above. A pin 9 is fitted on the lower end of the hook C. A coil spring 10 is fitted between the upper part of the jaw 4 and the sliding plate 8, and the coil spring 10 gives the hook C a downward elastic force. The upper half of the hook C is a ring-shaped hook c. The hook c is hooked on the L-shaped hook E attached to the carrier frame.

[0003] The above is used as follows. The tilt F, which has been lowered downward on the truck bed, is lifted and made vertical so that the L-shaped hook E protrudes from the recess g provided at the end of the fitting G attached to the tilt F. Then, the grip portion a of the handle A is lifted upward, the hook portion c of the hook C is passed through the L-shaped hook E, and then the grip portion a of the handle A is depressed.
The state shown in FIG. Coil spring 10
Is compressed, and the hook c is firmly hooked on the L-shaped hook E by its elasticity. When the hook c of the hook C is removed from the L-shaped hook E, the user grips the handle a of the handle A and lifts it. The hook c is loosened and disengaged from the L-shaped hook E, and the jaw 4 rotates downward together with the hook C about the pin 5. When the stopper 6 provided at the lower end of the jaw 4 hits the inner surface of the upper portion of the handle A, the rotation of the jaw 4 and the like is prevented, so that the jaw 4 and the like do not fall on the hand holding the handle A. by the way,
The handle A and the hook C shown in FIG.
It was manufactured as shown in FIG. That is, first, a sheet material is sheared to prepare a material having a predetermined size. Next, a predetermined outer shape of the handle A and the hook C is subjected to shearing processing. Also, a predetermined position is drilled by shearing. For the handle A, the grip portion a is bent. Finally, the outer peripheral burrs of both of them are removed in a separate process to obtain finished products.

[0004]

Heretofore, the handle A and the hook C have been manufactured by shearing from a plate material. For this reason, as is apparent from FIG. 11, the material yield was extremely poor, and was reduced to 50% or less.
In addition, it was mainly manual work, and mass production processing by an integrated process was difficult. In particular, the deburring process was a separate step, which further reduced the production efficiency. Further, since the handle A is made of a plate material, the grip of the grip portion a has a square shape, and the grip feel is poor. For this reason, the vinyl cover 3 had to be fitted to the grip portion a. However, the vinyl cover 3 often fell off during use. The problem to be solved by the present invention is to provide a method of manufacturing a handle and a hook of a truck carrier lifting latch which improves material yield, enables mass production processing in an integrated process, and incorporates deburring means in the integrated process. Is to do.

[0005]

The inventor of the present invention has studied the prior art from various angles. And as a raw material, we focused on a bar, not a plate. In addition, attention was paid to forging, bending, and shearing, and it was thought that the above problem would be solved by appropriately and effectively combining them. Then, as a result of repeating various studies and experiments in light of many years of experience, the present invention was able to be completed. The method of manufacturing the handle and hook of the truck carrier latch according to the present invention has solved such a problem, and will be described in detail below.

Referring to FIG. 1, the details of the process of manufacturing the handle A by the manufacturing method according to the present invention will be described. In addition,
Arrows indicate the order of each step. As the material, a solid or hollow bar is used. The material may be mild steel,
Stainless steel and aluminum alloy may be used. First,
A long bar is sheared to a predetermined length. (1) shows an example in which a solid bar is sheared to a predetermined length. Next,
The end of the material is chamfered with a die forging device that draws and deforms, such as a header / former. Chamfering grip a
May be applied only to the ends, or may be applied to both ends.
(2), (3) and (4) are examples in which the grip is applied only to the end of the grip portion a. The chamfered portion of the grip portion a needs to be sufficiently removed so that no burrs are generated at the peripheral edge when the grip portion a is bent later. The chamfer may be a C surface, an R shape, or another shape. The cross-sectional shape of the grip portion a is
(3) The shape of the bar may be used as it is as in (4), or the cross-sectional area may be reduced to be smaller than that of the raw material by a die forging apparatus for drawing deformation. Although it may be narrowed down to a round shape, it is most preferable to narrow down to an elliptical shape as in (2).
Note that the shape is not limited to an elliptical shape in a strict sense, and may be a cross-sectional shape such as an oval shape as long as the shape is a crushed circle. The other part b may be left in the shape of the bar as it is as in (2) and (3), or it may be round or square as shown in (4) by means of a draw-forging die forging device such as a header / former. The cross-sectional area may be reduced by narrowing down to. When one or both of the grip portion a and the other portion b are squeezed, the squeezing may be performed simultaneously with the chamfering, or may be squeezed after the chamfering.
(2) is an example in which squeezing is performed simultaneously with chamfering. The forging of the grip portion a and the other portion b described above may be die forging or free forging.

[0007] In this specification, "die forging" means that a mold in which a required shape is engraved is used, a material is put into the die, and the material is pressed and molded into a required shape. "Forging" means press-forming with a workpiece sandwiched between upper and lower flat molds. Next, the bending of the grip portion a will be described. The bending is performed by a transfer press or the like. Only the grip portion a may be bent, the other portion b may be bent simultaneously in the opposite direction to the bending of the grip portion a, or the grip portion a may have one or more bent portions. (5) is an example in which both are bent. If the cross-sectional shape of the bar is to be left as it is, it may be bent as it is. When one or both of the grip portion a and the other portion b are squeezed into an elliptical shape or the like, they may be bent into an elliptical shape or the like by compression forging. Their order may be reversed. In the case of an elliptical shape or the like, it is desirable to bend the major axis in the bending direction. When bending the grip portion a, it is desirable to use a bending means for preventing local crushing deformation due to compression. At the boundary between the grip portion a and the other portion b, a step may be provided in which the grip portion a is higher in a plane perpendicular to the bending direction of the grip portion a. The step may be inclined, or may be vertical or only the upper part may be vertical.

[0008] The bending apparatus must include means for using a bending press jig and a bending receiving jig whose inner peripheral shape is an arc following the peripheral shape of the workpiece. As the bending mechanism, as in an embodiment to be described later, a mechanism provided with means for suppressing the movement of the workpiece in the longitudinal direction and a link mechanism / cam mechanism may be employed. In the embodiment, the bending device is incorporated in the transfer press.
When incorporated into a transfer press, it is necessary to employ a horizontal bending mechanism that makes the bending direction horizontal from the point of automatically transporting the workpiece. Then, it is necessary to provide a mechanism in which the workpiece is held by upper and lower pressing jigs that can move up and down, and the workpiece is bent by left and right bending press jigs and bending receiving jigs that can be opened and closed right and left.

When bending is performed by a single press, a vertical bending mechanism that makes the bending direction vertical may be employed. In addition, there is also provided a receiving jig type and a pressing jig type that rotates and moves along the periphery of the receiving jig type, and a mechanism for winding a workpiece around the receiving jig type with the pressing jig type. Good. In the case of this mechanism, one end of the workpiece may be fixed. Or
The workpiece may be held by the pressing jig so that the receiving jig can be rotated, and the workpiece may be moved by feeding the workpiece in the longitudinal direction. Alternatively, a mechanism may be used in which two rotatable receiving jigs are used as both fulcrums, and the center thereof is pressed by a pressing jig to apply bending deformation to the workpiece. Whatever mechanism is used, it is necessary to take measures to prevent local crushing deformation due to compression. When the other portion b is narrowed down to a round shape or a square shape as shown in (4), the other portion b may have the same shape. When the bar shape is left as it is, the plate shape may be obtained by free forging by compression or die forging as shown in (7). The plate-shaped portion may be thinned by shearing as shown in (8). (9) When drilling a predetermined position as in (10), a shearing process may be used.

Next, a process of manufacturing the hook C by the manufacturing method according to the present invention will be described with reference to FIG. A solid bar is used as a material for the hook c, and the material is the same as that of the handle A. First, a bar is sheared to a predetermined length. Then, the end face of the hook C as a hook portion c may be chamfered by a die forging device such as a header former as shown in (2). The other portion d excluding the hook portion c may be drawn into a round shape or a square shape as in (2). Next,
As in (3), the hook portion c is formed into a plate shape by free forging by compression using a transfer press or the like. The end face of the plate-shaped part may be left as it is,
Shearing may be performed. The plate-shaped portion may be punched out by shearing, and thereafter, a lower corner may be chamfered around the punched-out portion using a die forging device to form shapes such as (4) and (5). As in (6), the punched portion may be expanded from the inside to the outside by die forging. At this time,
At the same time, the upper peripheral corner may be chamfered, or the upper peripheral corner may be chamfered after expansion. Further, the order of chamfering of corners may be reversed or may be simultaneous. A cam mechanism or the like may be employed as a device for expanding the punched portion. When drilling of a predetermined position is necessary as in (7), it can be performed by shearing. The hook c may be bent downward as shown in FIG. 9 described later.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for manufacturing a handle A will be described. The material is JISG3507 SWRCH
A rod material having a coil shape of 12R and a diameter of 18.65 mm is used. An 80 hp cold header is used as the device. First, a bar material is cut into 1
A workpiece cut to a length of 61 mm is prepared. Then, as shown in FIG. 3A, the end surface of the portion to be the grip portion a is chamfered by die forging processing of drawing deformation by the die 11 and the first punch 12. Next, as shown in FIG. 3 (b), the die 11 and the second punch 13 are subjected to drawing deformation forging at a portion to be the grip portion a to form an elliptical shape. Thereafter, a work bar (not shown) is inserted from the right side of the hole of the die 11 and pressed to the left side, so that the work is protruded to the left and pulled out. Next, the workpiece is conveyed to a 5000 kilonewton transfer press and bent. FIG. 4A is a vertical sectional view schematically showing a bending die and a bending mechanism incorporated in a transfer press, and FIG. 4B is a horizontal sectional view schematically showing a bending die portion. is there. These figures show the state after the completion of bending. Before the start of the bending process, the pressing plate 14 horizontally arranged above and the cam 15 attached to the lower left of the pressing plate 14 are above the position shown in FIG. The workpiece is placed on the lower holding jig 16 at the center where the bending is not performed. The lower holding jig 16 is supported by a coil spring provided below the lower holding jig 16 so that it can move up and down. The upper holding jig 16 is attached to the pressing plate 14 via a coil spring at a position directly above the lower holding jig 16. The illustration of the upper holding jig 16 and the upper and lower coil springs is omitted.

Before the start of bending, the lower holding jig 16 is pushed upward by the coil spring, and the workpiece on the holding jig 16 is also at a position higher than that of FIG. . Each of the bending receiving jig 17 and the bending pressing jig 18 has a mechanism that opens to the left and right by a coil spring (not shown), and the inner surfaces thereof are shaped to follow the outer peripheral shape of the workpiece. ing. The link 19 is located at a position shown by a two-dot chain line in FIG. In addition, in order not to move in the longitudinal direction when bending, the end of the other portion b of the workpiece is moved toward the stopper 20 attached to the bending receiving jig 17 as shown in FIG. . Pressure plate 14 and cam 1
When 5 is lowered, the upper holding jig 16 is also lowered to hold the upper part of the workpiece. The workpiece is held by the upper and lower holding jigs 16, and thereafter, the coil spring attached to the lower holding jig 16 is compressed and contracted, so that the workpiece is lowered while being held, and FIG. Stop at the predetermined position shown in (a). When the cam 15 further moves down, the bending jig 17 is pushed by the cam 15 and moves rightward, and then the bending jig 17 stops at a predetermined position. At the stop, the lower end of the cam 15 pushes the upper end of the left portion of the link 19, so that the link 19 rotates to the position indicated by the solid line. The right part of the link 19 pushes the bending and pressing jig 18 to the left, and presses the workpiece against the bending receiving jig 17 to give a bending process, and the state shown in FIGS. (Note that cam 15
The function of pressing the bending receiving jig 17 to the right and the function of pressing the upper end of the left portion of the link 19 are both performed, thereby making the apparatus compact. )

After the bending, the pressure plate 14 and the cam 15 are raised, and the link 19 is pushed by the lower left coil spring to return to the position indicated by the two-dot chain line. The bending receiving jig 17 and the bending pressing jig 18 are also opened right and left by the force of the coil springs attached to each. Also, the upper and lower holding jigs 16 are pushed by the lower coil springs, and the workpiece is also raised. Eventually, the lifting of the lower holding jig 16 ends, but the upper holding jig 16 further rises a little further together with the pressure plate 14 to release the holding of the workpiece, and the workpiece is transported to the next step. . In the next step, the other portion b is formed into a 9 mm thick plate by compression free forging. Further, a predetermined position is drilled by shearing in the next step. FIG. 5 is a reduced view of the handle A thus completed, wherein (a) is a front view and (b) is a bottom view.
The entry of dimensions was omitted.

Next, an embodiment of a method of manufacturing the hook C will be described. As in the case of handle A, the material is JIS G3507 SWRCH 12R diameter 1
Performed with an 80 hp cold header using 8.65 mm bars. First, 6
The workpiece cut to a length of 6.6 mm is inserted into the die 22 by the first punch 21 as shown in FIG. Next, as shown in FIG.
The other part d excluding the part to be hooked c by 3 is subjected to drawing deformation die forging so as to have a cross-sectional area of 13.5 × 9 mm and a length of 77 mm. Then, the die 22 is moved by the bar 24 moving from the right side through the hole of the die 22.
The workpiece to the left of, and pull it out. Next, 500
The work is transported to a transfer press of 0 kilonewton. Then, the portion of the hook portion c is formed into a 9 mm-thick plate by compression free forging. Next, the center of the hook portion c is punched out by shearing, and the lower edge is chamfered by die forging to obtain the one shown in FIG.

Next, as shown in FIG. 8, the hook portion c incorporated in the transfer press is held between the mold 25 and the lower mold 26 by the force of a spring (not shown).
The upper surface of the hole formed in the hook portion c is provided with a taper for processing the C surface, and a punch 27 having a tapered tip is pushed in from above to expand the hook portion c from the inside to the outside, and at the same time, to increase the inside angle of the upper portion. Chamfering. After that, when the hook portion c is bent nine times, the one shown in FIG. 9 is completed. 9A and 9B show a completed product of the hook C. FIG. 9A is a plan view, and FIG. 9B is a cross-sectional view of the hook C which is cut vertically. Dimensions are omitted. Note that the nine-degree bending is for making the hook C easily hooked on the L-shaped hook E. Next, Table 1 shows material yields in the case of using the manufacturing method introduced as an example and in the case of using the conventional method. The material yield means (product weight / material weight × 100). In addition, Table 2 shows a comparison between the two with regard to the production time per piece.

[0016]

[Table 1]

[0017]

[Table 2]

From Table 1, it can be seen that the material yield in the case of the embodiment method is 2-2.
It turns out that it is 5 times. From Table 2, it can be seen that the production time in the case of the example method is only about one third of the conventional method for the handle A and only about one fifth for the hook C. It can be said that the material yield and production efficiency in the case of the embodiment method are remarkably higher than those of the conventional method. In particular, as clearly shown in FIG. 5, at the boundary between the grip portion a of the handle A and the other portion b, there is a step at which the grip portion a is higher in a plane perpendicular to the bending direction of the grip portion a. Provided. Step is hook C
It acts as a fall prevention when the vehicle falls down backwards, and prevents the hand holding the handle A from being harmed. Also,
Since the grip portion a has an elliptical cross section and a bending direction in the major axis direction, the grip feel is good. That is, the operability of the handle A is extremely good.

[0019]

In the manufacturing method according to the present invention, a bar is used as a raw material, and forging including drawing deformation, die forging of burr processing, bending and shearing are appropriately and effectively combined. , Mass production processing by an integrated process becomes possible. Therefore, the production time can be shortened, and the productivity is excellent. Also, the material yield is significantly improved. In the case of the handle manufacturing method according to the present invention, when the grip portion a is manufactured by a method including a compression forging process of narrowing a portion to be a grip portion a to a cross-sectional shape such as an elliptical shape obtained by crushing a circle, the grip portion a is Because it has an elliptical shape, it has a good grip.
Further, in the case where the major axis direction of the cross-sectional shape such as the elliptical shape in which the circle is crushed at the portion to be the grip portion a is manufactured by using the bending direction, the grip feeling of the grip portion a is further improved. . Also, in the case of a manufacturing method in which a step where the grip portion a is higher in a plane perpendicular to the bending direction of the grip portion a is provided at a boundary between the portion to be the grip portion a and the other portion b, the step is provided. The step prevents the hook C or the like from falling down and prevents the hit on the hand holding the handle A.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing each step of manufacturing a handle A by a manufacturing method according to the present invention.

FIG. 2 is a conceptual diagram showing each step of manufacturing a hook C by a manufacturing method according to the present invention.

FIG. 3 is a cross-sectional view showing a part of a method of manufacturing the handle A according to an embodiment;

FIG. 4 is a vertical and horizontal sectional view showing another partial step of the method of the embodiment.

FIG. 5 is a front view and a bottom view showing a handle A manufactured by the method of the embodiment.

FIG. 6 is a sectional view showing a part of a method of manufacturing the hook C according to one embodiment.

FIG. 7 is a plan view and a sectional view showing an intermediate product of the hook C manufactured by the method of the embodiment.

FIG. 8 is a cross-sectional view showing a step of subjecting the intermediate product shown in FIG. 7 to final processing.

FIG. 9 is a plan view and a cross-sectional view showing a hook C completed through the process.

FIG. 10 is a perspective view showing a conventional tilt stopper.

FIG. 11 is a plan view showing a part of a manufacturing process of a handle A and a hook C of a conventional anti-lifting latch.

[Explanation of symbols]

 A handle a grip part b other part C hook c hook part d other part

Claims (6)

(57) [Claims] 1. A bar material is cut to a predetermined length by shearing, a portion to be a grip portion a is bent, and an end of the portion is chamfered. The method for manufacturing a handle of a truck bed latch which is characterized in that the other portion (b) is formed into a plate by compression forging, and a hole is formed in a predetermined position of the plate-shaped portion. 2. A truck carrier platform latch according to claim 1, further comprising a compression forging process for narrowing a portion to be the grip portion a to a cross-sectional shape such as an elliptical shape obtained by crushing a circle. Handle making method. 3. The handle of the truck bed swinging latch according to claim 2, wherein a major axis direction of a cross-sectional shape such as an elliptical shape in which a circle is crushed at a portion serving as a grip portion a is set as a bending direction. Law. 4. A step in which the grip portion a is higher in a plane perpendicular to the bending direction of the grip portion a at a boundary between a portion to be the grip portion a and the other portion b. 2
Or, the method of manufacturing a handle of the truck carrier swing stop latch according to 3. 5. A method in which a bar is cut into a predetermined length by shearing, a portion to be hooked c is formed into a plate by compression forging, and a middle portion of the plate is punched by shearing. Features a method of manufacturing hooks for the truck carrier lifting latch. 6. The method of claim 5, wherein a portion formed by shearing a middle portion of the plate-shaped portion is expanded from the inside to the outside.