JP7748302B2 - Crimping tools - Google Patents

Description

The present invention relates to a crimping tool used to crimp objects such as air conditioning pipes and pipe joints for cold and hot water supply pipes, and in particular to a crimping tool in which a yoke die facing a press die is connected to the head portion via a connecting pin.

This type of crimping tool has a semi-annular press die and yoke die mounted on the head portion at the tip of the tool body (see Patent Documents 1 to 4, etc.). The press die is held in the widthwise center of the head portion so that it can move back and forth. The yoke die faces the press die on the tip side of the press die. The widthwise end of the head portion and the widthwise end of the yoke die are connected via a connecting pin (slide pin). The connecting pin can be pulled out from at least the yoke die, which allows the yoke die to be released from the head portion. A pipe fitting or other object to be crimped is sandwiched between the released yoke die and press die, and then the yoke die is reconnected to the head portion via the connecting pin. The press die is then driven forward to crimp the object to be crimped.

Japanese Patent Application Laid-Open No. 2008-132516 JP 2013-066897 A JP 2013-249848 A JP 2011-224738 A

In conventional crimping tools, even if the yoke die is not set in the correct position, it is possible to attach the connecting pin to the head (empty attachment). Therefore, if the object to be crimped is crimped in an empty attachment state, there is a possibility that a crimping defect will occur.
Furthermore, the connecting pin is provided with a rotary locking mechanism, but if the connecting pin rotates due to an unexpected rotational force during construction and the lock is released, there is a risk that the yoke die will fall.
In view of the above circumstances, the present invention has as its first object to prevent the connecting pin from being installed without being attached, and as its second object to prevent the connecting pin from being easily released by an unexpected rotational force.

In order to achieve the first object, the present invention provides a crimping tool for crimping an object by clamping it between a press die held so as to be movable back and forth in a central portion in a width direction of a head portion at the tip of a tool body, and a yoke die connected to a connecting portion on a side portion of the head portion in the width direction via a connecting member,
An engagement pin hole is formed in the connecting portion, and an engagement pin is provided on an inner peripheral surface of the engagement pin hole,
a lock pin hole communicating with the engagement pin hole is formed in a connected portion of the yoke die that is connected to the connecting portion, and a lock pin is provided on an inner peripheral surface of the lock pin hole,
the connecting member has a connecting pin that is movably passed through the engagement pin hole and the locking pin hole, and a biasing means that biases the connecting pin relative to the head portion in a direction from the pin tip side toward the pin head side along the axial direction of the connecting pin,
an outer peripheral surface of the connecting pin is formed with an engagement guide groove that extends in the axial direction and guides the engagement pin, a lock guide groove that extends parallel to the engagement guide groove and guides the lock pin, and a lock groove that extends from an end of the lock guide groove on the pin head side in the circumferential direction of the connecting pin ,
When the engagement pin is at the end of the engagement guide groove on the pin head side, the connecting pin is allowed to rotate,
The rotation causes the lock pin to be locked in the lock groove, preventing the connecting pin from sliding toward the pin head by the biasing means, while the engaging pin allows the sliding.

When the yoke die is attached to the head portion of the crimping tool, the connected portion of the yoke die is fitted into the connecting portion of the head portion, and the locking pin hole of the yoke die is aligned with the engaging pin hole of the head portion.
Next, the connecting pin is inserted from the engaging pin hole into the locking pin hole, with the engaging pin being guided along the engaging guide groove of the connecting pin, and the locking pin being guided along the locking guide groove.
When the engagement pin reaches the end of the engagement guide groove on the pin head side, the connecting pin is rotated to lock the lock pin into the lock groove. This locks the connecting pin so that it cannot slide axially (prevents it from coming out). As a result, the yoke die is properly attached to the head portion, allowing for smooth crimping of the target object.
On the other hand, if the connecting pin is not inserted into the locking pin hole due to improper installation of the yoke die and the lock pin is not locked by the lock groove, even if the engagement pin is engaged with the connecting pin, the biasing force of the biasing means will cause the connecting pin to slide toward the pin head and pop out. This solves the first problem of preventing empty installation of the connecting pin. The worker can recognize the improper installation of the yoke die and avoid performing the crimping operation with the improper installation.

Preferably, a circumferential groove is formed on the outer peripheral surface of the connecting pin, extending in the circumferential direction from the end of the engagement guide groove on the pin head side, and the groove edge of the circumferential groove on the pin tip side is inclined toward the pin tip toward the engagement guide groove.
As a result, after the engagement pin reaches the end of the engagement guide groove on the pin head side, the connecting pin is rotated to receive the engagement pin into the circumferential groove. At this time, if the lock pin and lock groove are not locked due to improper installation of the yoke die, the circumferential component of the biasing force of the biasing means will cause the engagement pin to return along the inclined groove edge into the engagement guide groove, and the biasing force will then cause the connecting pin to slide toward the pin head and pop out. This reliably prevents the connection pin from being installed vacantly.

Preferably, the outer peripheral surface of the connecting pin is formed with a circumferential groove extending in the circumferential direction from the end of the engagement guide groove on the pin head side, and a reverse guide groove extending in the axial direction from the end of the circumferential groove on the opposite side to the engagement guide groove side toward the pin tip side.
As a result, when the yoke die is improperly installed, if the engaging pin is positioned at the pin head end of the engaging guide groove and then the connecting pin is turned, the engaging pin will reach the reverse guide groove via the circumferential groove. Then, due to the biasing force of the biasing means, the engaging pin will slide relatively along the reverse guide groove toward the pin tip, and the connecting pin will slide toward the pin head and pop out. As a result, void installation of the connecting pin can be reliably prevented.

Preferably, a return groove portion is provided at an end of the lock groove opposite to the lock guide groove side, the return groove portion being directed toward the tip of the pin.
As a result, when the yoke die and connecting pin are properly installed, the lock pin fits into the return groove, reliably locking the connecting pin (preventing it from coming loose). Even if an unexpected rotational force acts on the connecting pin in this state, the lock pin is constrained by the return groove so that it cannot move relative to the circumferential direction of the connecting pin. This prevents the connecting pin from rotating and unlocking. To unlock the pin, the connecting pin is pushed toward the pin tip against the biasing force of the biasing means to remove the lock pin from the return groove. Then, the connecting pin is rotated to guide the lock pin from the lock groove into the lock guide groove. In other words, because unlocking requires a two-step operation—pushing and pulling in the axial direction and rotating—the connecting pin is prevented from being easily unlocked. This solves the second problem of preventing the connecting pin from being easily unlocked by unexpected rotational force.

This invention prevents empty installation of the connecting pin, and avoids the occurrence of poor crimping when the object to be crimped is crimped in an empty installation state.

FIG. 1 is a side view of a crimping tool according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the working portion of the crimping tool. FIG. 3(a) is a vertical cross-sectional view of the action portion taken along line IIIa-IIIa in FIG. FIG. 3(b) is a cross-sectional view of the action portion taken along line IIIb-IIIb in FIG. 3(a). 4 shows the connecting pin of the crimping tool, where FIG. 4(a) is a side view taken along line IVa-IVa in FIG. 4(d), FIG. 4(b) is a plan view taken along line IVb-IVb in FIG. 4(a), FIG. 4(c) is a side view taken along line IVc-IVc in FIG. 4(b), FIG. 4(d) is a bottom view taken along line IVd-IVd in FIG. 4(c), and FIG. 4(e) is a perspective view. 5(a) to 5(c) are explanatory diagrams sequentially showing how to correctly attach a connecting pin in a state where the yoke die of the crimping tool is correctly assembled to the head portion. FIG. 6 is an explanatory diagram showing the initial operation of unlocking. 7(a) to 7(c) are explanatory diagrams sequentially showing how the connecting pin is installed. 8(a) to 8(c) are explanatory views sequentially showing how to correctly attach a connecting pin in a state where the yoke die of the crimping tool according to the second embodiment of the present invention is correctly assembled to the head portion. 9A to 9C are explanatory views sequentially showing how the connecting pin according to the second embodiment is pre-mounted.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
First Embodiment (FIGS. 1 to 7)
1 shows a crimping tool 1 according to this embodiment. The crimping tool 1 includes a tool body 2 and a crimping portion 3.

<Tool body 2>
As shown in Fig. 1, the tool body 2 includes a casing 2c extending along the axis L and a grip 2g protruding laterally from the casing 2c. The casing 2c houses an advance/retract drive unit 4. A cylinder 4c of the advance/retract drive unit 4 is provided at the axial tip (upper end in Fig. 1) of the casing 2c. A piston 4p (output shaft of the advance/retract drive unit) is housed in the cylinder 4c. The cylinder 4c and the piston 4p are arranged on the axis L. The piston 4p protrudes from the cylinder 4c to the tip side (upper side in Fig. 1). The advance/retract drive unit 4 drives the piston 4p to advance/retract along the axis L.

<Crimping action part 3>
As shown in Fig. 1, a crimping section 3 is provided at the axial tip of the casing 2c (the upper end in Fig. 1). The crimping section 3 includes a head section 10, a press die 20, and a yoke die 30. The press die 20 and the yoke die 30 can be separated from and assembled to the head section 10.
In the following description, unless otherwise specified, it is assumed that the press die 20 and the yoke die 30 are correctly assembled to the head portion 10.

<Head unit 10>
1 and 2, the head portion 10 includes a shaft hole 10c, a retaining recess 11, and a pair of connecting portions 13, and is formed in a roughly V-shape or semi-annular shape. The space in the center of the head portion 10 in the width direction forms the retaining recess 11. The shaft hole 10c passes through the center of the head portion 10 in the axial direction and is connected to the retaining recess 11. A cylinder 4c is fitted into the shaft hole 10c.

As shown in Figures 1 and 2, a pair of connecting portions 13 for connecting to the yoke die 30 is provided on both sides of the head portion 10 in the width direction (left and right in Figure 1) across the retaining recess 11. Each connecting portion 13 has two connecting plate portions 14. The two connecting plate portions 14 face each other in the thickness direction of the head portion 10 (the direction perpendicular to the paper surface in Figure 1). A connecting recess 15 is formed between these connecting plate portions 14. The connecting recess 15 opens at the tip surface (top surface in Figure 1) of each side of the head portion 10 in the width direction and extends in the width direction to reach the outer and inner surfaces of the head portion 10.

As shown in Figure 3(a), the connecting portion 13 has engagement pin holes 17 formed therein. The engagement pin holes 17 penetrate each of the two opposing connecting plate portions 14 in the thickness direction (the direction perpendicular to the paper surface in Figure 1). The two engagement pin holes 17 are arranged on the same axis along the thickness direction. A connecting recess 15 is interposed between the two engagement pin holes 17. Each engagement pin hole 17 is connected to a connecting recess 15.
As shown in Figure 3(a), when distinguishing between two connecting plate portions 14 and two engaging pin holes 17 facing each other in the thickness direction, the connecting plate portion 14 and engaging pin hole 17 on the front side (right side in the figure) are marked with "A" and the connecting plate portion 14 and engaging pin hole 17 on the back side (left side in the figure) are marked with "B".

As shown in Figure 3(a), an engagement pin 50 and engagement spring 51 are embedded inside the front-side connecting plate portion 14A. The engagement pin 50 is located, for example, below the engagement pin hole 15 and can extend and retract from the inner surface of the engagement pin hole 17A. The engagement spring 51 is located at the bottom of the engagement pin 50 and biases the engagement pin 50 in a direction that causes it to protrude into the engagement pin hole 17A.

<Press die 20>
As shown in Fig. 1, a press die 20 is housed in the holding recess 11 of the head portion 10 and is held so as to be movable back and forth in the axial direction (the up-down direction in Fig. 1). The press die 20 is formed in a roughly semi-annular shape. Three (plural) compression protrusions 21 are formed on the inner surface of the press die 20 so as to extend in the circumferential direction.

As shown in Figure 1, a connection hole 25 (connection portion) is formed in the center of the press die 20. The piston 4p of the advance/retract drive unit 4 passes through the head portion 10 and is fitted into the connection hole 25. This detachably connects the press die 20 and the piston 4p. In turn, the press die 20 is detachably connected to the head portion 10 via the piston 4p and cylinder 4c. The press die 20 advances and retreats in the axial direction (up and down in Figure 1) by the advance/retract drive of the piston 4p.

<York Die 30>
1 and 2, the yoke die 30 is formed in a roughly semi-annular shape with an outer diameter larger than that of the press die 20 and an inner diameter equal to that of the press die 20. The yoke die 30 is disposed so as to face the press die 20 on the tip side (upper side in FIG. 1) of the press die 20. A plurality of compression protrusions 31 are formed on the inner surface of the yoke die 30 so as to extend in the circumferential direction.

As shown by the two-dot chain line in Figure 1, the object to be crimped 9 is sandwiched between the yoke die 30 and the press die 20 and crimped. While detailed illustration is omitted, the object to be crimped 9 is, for example, a pipe fitting into which the end of an air-conditioning pipe or a cold/hot water supply pipe is inserted. By crimping the outer periphery of the pipe fitting so as to compress it radially, the pipe fitting and the pipe end are connected in an airtight or liquid-tight manner. The crimping tool 1 is particularly suitable for crimping large-diameter pipe fittings.

As shown in Figures 1 and 2, a pair of connecting arms 33 (connected portions) are provided on both widthwise sides of the yoke die 30. Each connecting arm 33 is fitted into a corresponding connecting recess 15.

A locking pin hole 37 is formed in the connecting arm 33. The locking pin hole 37 penetrates the connecting arm 33 in the thickness direction (the direction perpendicular to the plane of the paper in Figure 1). Each locking pin hole 37 is aligned and communicates with the engagement pin hole 17 of the corresponding connecting part 13. A connecting pin 41 (described below) is inserted into the communicating pin holes 17, 37, thereby connecting each connecting arm 33 to the corresponding connecting part 13.

As shown in Figure 3(b), a lock pin 60 is embedded in the connecting arm 33. The lock pin 60 is disposed on one circumferential side (for example, a lateral portion) of the lock pin hole 37. The tip of the lock pin 60 protrudes from the inner circumferential surface of the lock pin hole 37. A threaded portion 61 is provided at the base end of the lock pin 60. The threaded portion 61 is threaded into the female threaded hole 36 of the connecting arm 33.
The lock pin 60 is offset from the engagement pin 50 by, for example, about 90 degrees in the circumferential direction of the pin holes 17 and 37 .

<Connecting member 40>
1, a connecting member 40 is provided on each of both widthwise sides of the crimping portion 3. The connecting portion 13 of the head portion 10 and the connecting arm 33 (connected portion) of the yoke die 30 are detachably connected via the connecting member 40.

As shown in FIG. 2, each connecting member 40 includes a connecting pin 41, a cap 42, and a compression coil spring 43 (biasing means). As shown in FIGS. 3(a) and 3(b), the axial direction of the connecting pin 41 is oriented in the thickness direction of the crimping portion 3. The connecting pin 41 is movably inserted through the engagement pin hole 17 and the locking pin hole 37. The pin tip 41e of the connecting pin 41 faces the back side of the crimping portion 3 (left side in FIG. 3) and forms an end surface that is approximately flush with the back surface 12b of the head portion 10. The pin head 41a of the connecting pin 41 faces the front side of the crimping portion 3 (right side in FIG. 3) and protrudes from the front surface 12a of the head portion 10. A cap 42 is attached to the pin head 41a. The cap 42 and connecting pin 41 are prevented from rotating relative to each other by a cross pin 49.

As shown in Figures 3(a) and 3(b), a compression coil spring 43 is fitted around the outer periphery of the connecting pin 41 near the pin head 41a. The spring 43 is housed in the annular gap 42c between the peripheral side of the cap 42 and the outer periphery of the connecting pin 41, and in a compressed state, one end abuts against the top plate of the cap 42 and the other end abuts against the head portion 10. As a result, the spring force (biasing force) of the spring 43 acts to protrude the connecting member 40 toward the front side of the head portion 10 (from the pin tip side toward the pin head side).

As shown in Figures 4(a) to 4(e), two guide grooves 44, 46 are formed on the outer peripheral surface of the connecting pin 41. As shown in Figure 4(d), the engagement guide groove 44 extends in the axial direction of the connecting pin 41. The end of the engagement guide groove 44 on the pin tip side (left side in Figure 4(d)) is closed and does not reach the pin tip 41e. The end of the engagement guide groove 44 on the pin head side (right side in Figure 4(d)) is located in the middle of the connecting pin 41 in the axial direction.

A circumferential groove 45 connects to the end of the engagement guide groove 44 on the pin head side. As shown in Figures 4(a) to 4(c), the circumferential groove 45 intersects with the engagement guide groove 44 and extends approximately half to three-quarters of the circumference of the connecting pin 41 in the circumferential direction. The groove edge 45a of the circumferential groove 45 on the pin head side extends straight along the circumferential direction of the connecting pin 41. The groove edge 45e of the circumferential groove 45 on the pin tip side is inclined toward the engagement guide groove 44 and toward the pin tip 41e. As a result, the groove width of the circumferential groove 45 increases as it approaches the engagement guide groove 44.

As shown in Figure 4(e), a lock guide groove 46 is disposed on the outer periphery of the connecting pin 41, offset approximately 90 degrees from the engagement guide groove 44 in the circumferential direction of the connecting pin 41. As shown in Figures 4(a) and 4(b), the lock guide groove 46 extends parallel to the engagement guide groove 44 along the axial direction of the connecting pin 41. The end of the lock guide groove 46 on the pin tip side (left side in Figure 4(a)) reaches the pin tip 41e. The end of the lock guide groove 46 on the pin head side (right side in Figure 4(a)) is disposed midway between the engagement guide groove 44 in the axial direction of the connecting pin 41. The lock guide groove 46 is shorter than the engagement guide groove 44.

As shown in Figure 4(b), a lock groove 47 connects to the end of the lock guide groove 46 on the pin head side (right side in Figure 4(b)). The lock groove 47 intersects with (or crosses) the lock guide groove 46, extending approximately 90 degrees circumferentially around the connecting pin 41 and in the same direction as the circumferential groove 45. The lock groove 47 is shorter than the circumferential groove 45. Both edges of the lock groove 47 extend straight along the circumferential direction of the connecting pin 41.

As shown in Figure 4(b), a return groove portion 48 is provided at the end of the lock groove 47 opposite the lock guide groove 46 side. The return groove portion 48 is semicircular and extends from the lock groove 47 toward the pin tip (left side in Figure 4(b)). The return groove portion 48 is sufficiently shorter than the lock guide groove 46.

As shown in Figures 5(a) to 5(c), the engagement pin 50 of the head portion 10 is movably fitted into the engagement guide groove 44 and the circumferential groove 45. As shown in Figure 3(a), when the crimping portion 3 is in an assembled state, the engagement pin 50 is received in the circumferential groove 45. However, as shown in Figure 7(b), because the groove edge 45e of the circumferential groove 45 is inclined, when the engagement pin 50 is pressed against the groove edge 45e by the spring force of the spring 43, the engagement pin 50 attempts to slide along the groove edge 45e toward the engagement guide groove 44. Therefore, even when the engagement pin 50 is received in the circumferential groove 45, the spring 43 allows the connecting pin 41 to slide toward the front side (to the right in Figure 7(b)).

As shown in Figures 5(a) to 5(c), the lock pin 60 of the yoke die 30 fits movably into the lock guide groove 46 and the lock groove 47. As shown in Figure 3(b), when the yoke die 30 is assembled to the head portion 10, the lock pin 60 is engaged and positioned in the lock groove 47. Furthermore, as shown in Figure 5(c), the spring force of the spring 43 biases the connecting pin 41 toward the front side, causing the lock pin 60 to enter the return groove portion 48 of the lock groove 47 and press against the semicircular edge of the return groove portion 48. This prevents the connecting pin 41 from sliding further toward the front side (to the right in Figure 3(b)), locking the connecting member 40 so that it cannot be inserted or removed from the pin holes 17 and 37. This in turn prevents the head portion 10 and the yoke die 30 from separating from each other.

As shown in FIG. 1, when the workpiece 9 is to be crimped using the crimping tool 1, the workpiece 9 is sandwiched between the press die 20 and the yoke die 30 while the crimping portion 3 is being assembled.
5(a), in the pre-assembly state, the spring force of the spring 43 causes the connecting member 40 to protrude significantly toward the front side of the head portion 10 (to the right in the figure). The pin tip 41e faces the connecting recess 15 from the front-side engaging pin hole 17A. The engaging pin 50 abuts against the closed end of the engaging guide groove 44 on the pin tip side, preventing the connecting member 40 from slipping out of the head portion 10. The connecting recess 15 is open, with the connecting pin 41 unable to enter.

As shown in FIG. 5( a ), the yoke die 30 is inserted into the opened connecting recess 15 , and the locking pin holes 37 of the yoke die 30 are aligned with the engaging pin holes 17 of the head portion 10 .
Next, as shown in FIG. 5B , the connecting pin 41 of the connecting member 40 is inserted from the front-side engaging pin hole 17A into the locking pin hole 37 against the spring force of the spring 43. As the insertion operation occurs, the engaging pin 50 is guided along the engaging guide groove 44 of the connecting pin 41, and the locking pin 60 is introduced into the locking guide groove 46 of the connecting pin 41. At this time, the connecting pin 41 is unable to rotate due to the engagement between the engaging pin 50 and the engaging guide groove 44, so there is no angular misalignment between the locking pin 60 and the locking guide groove 46, and the locking pin 60 can be smoothly introduced into the locking guide groove 46. Thereafter, as the connecting member 40 is inserted, the locking pin 60 is guided along the locking guide groove 46.

Eventually, the engagement pin 50 reaches the end of the engagement guide groove 44 on the pin head side, and at the same time, the lock pin 60 reaches the end of the lock guide groove 46 on the pin head side. This prevents the connecting pin 41 from being inserted any further. At this point, the pin tip 41e of the connecting pin 41 is inserted into the engagement pin hole 17B of the rear connecting plate portion 14B.

5(c), the connecting pin 41 is rotated to receive the engaging pin 50 into the circumferential groove 45, and the lock pin 60 is guided into the lock groove 47. After the lock pin 60 is guided to the innermost end of the lock groove 47 (the end opposite the lock guide groove 46), the connecting member 40 is released, and the lock pin 60 fits into the return groove portion 48 due to the bias of the spring 43 and is pressed against the tip of the return groove portion 48. This puts the connecting pin 41 into a locked state where it cannot rotate and is prevented from coming out. As a result, the yoke die 30 is properly attached to the head portion 10.
Thereafter, the press die 20 is driven forward by the forward/backward driving unit 4 to crimp the pipe joint 20 (object). Since the yoke die 30 is correctly attached, the crimping operation can be carried out smoothly.

Even if an unexpected rotational force acts on the connecting member 40 when the yoke die 30 is correctly installed, the lock pin 60 is constrained by the return groove 48 so that it cannot move relative to the connecting pin 41 in the circumferential direction, preventing the connecting member 40 from rotating and releasing the lock.

As shown in Figure 6, to release the lock, the connecting member 40 is slightly pushed backward (to the left in the figure) against the spring 43. This causes the lock pin 60 to be ejected from the return groove portion 48. Then, by rotating the connecting member 40 in the opposite direction from when it was assembled, the lock pin 60 is guided from the lock groove 47 to the lock guide groove 46, and the engagement pin 50 is guided from the circumferential groove 45 to the engagement guide groove 44 (Figure 5(b)). This releases the locked state.

In other words, unlocking requires a two-step operation: pushing and pulling the connecting member 40 in the axial direction, and then rotating it, which prevents the connecting member 40 from being unlocked easily. As a result, the lock on the connecting pin 41 can be prevented from being easily released by unexpected rotational force.

When the lock is released, the connecting member 40 jumps out to the front side (the right side in FIG. 5(a)) due to the spring force of the spring 43. At this time, the connecting pin 41 comes out of the rear side engaging pin hole 17B and the locking pin hole 37, and is now fitted only into the front side engaging pin hole 17A (FIG. 5(a)). As a result, the lock pin 60 is released by being disengaged from the lock guide groove 46. This allows the yoke die 30 to be separated from the head portion 10.
As shown in Figure 5(a), the engagement pin 50 abuts against the closed end on the pin tip side of the engagement guide groove 44. This restricts the connecting member 40 from moving further toward the front side (to the right in Figure 5(a)), and prevents it from slipping out of the head portion 10.

On the other hand, as shown in Figure 7(a), when assembling the crimping tool 1, suppose the yoke die 30 is improperly installed (including not installed at all) and the connecting pin 41 is inserted into the rear engagement pin hole 17B against the bias of the spring 43. In this case, because the connecting arm 33 is not fitted into the connecting recess 15, the connecting pin 41 is not inserted into the locking pin hole 37 (Figure 5(c)), and the lock pin 60 (Figure 5(c)) and the lock groove 47 are not engaged.

In this state, when the engaging pin 50 is placed in the circumferential groove 45 and then the connecting pin 41 is released, the spring force of the spring 43 presses the engaging pin 50 against the inclined groove edge 45e of the circumferential groove 45, as shown in Fig. 7(b) . The component of the pressing force along the circumferential direction of the connecting pin 41 rotates the connecting pin 41, causing the engaging pin 50 to slide relatively from the circumferential groove 45 toward the engaging guide groove 44. Furthermore, as shown in Fig. 7(c) , the spring force of the spring 43 causes the engaging pin 50 to slide relatively toward the pin tip along the engaging guide groove 44, causing the connecting pin 41 to protrude from the head portion 10 to the front side (the right side in the figure).
This reliably prevents vacant mounting of the connecting pin 41. The worker can recognize improper mounting of the yoke die 30 and can avoid performing the crimping operation while the yoke die 30 is still improperly mounted.

Next, other embodiments of the present invention will be described. In the following embodiments, the same reference numerals will be used in the drawings to designate the same components as those already described, and the description thereof will be omitted.
Second Embodiment (FIGS. 8 and 9)
8A, in the crimping tool 1B according to the second embodiment, a reverse guide groove 71 is formed on the outer peripheral surface of the connecting pin 41. The reverse guide groove 71 is continuous with the end of the circumferential groove 45 on the side opposite to the engaging guide groove 44 (the lower side in the figure), and extends straight from there along the axial direction of the connecting pin 41 toward the pin tip 41e. The reverse guide groove 71 has a length that is at least half the length of the engaging guide groove 44. Furthermore, the reverse guide groove 71 is sufficiently longer than the return groove portion 48 of the lock groove 47, having a length several to ten times longer than the return groove portion 48.

The groove edge of the circumferential groove 45 on the pin tip side (left side in Figure 8(a)) is bent in the middle, with the portion closer to the engagement guide groove 44 than the bent portion 45c being an inclined groove edge 45e, and the portion closer to the reverse guide groove 71 than the bent portion 45c being an inclined groove edge 45b. The inclined groove edge 45b is inclined toward the pin tip side (left side in Figure 8(a)) as it approaches the reverse guide groove 71.

As shown in Figures 8(a) to 8(c), when the yoke die 30 is correctly attached to the crimping tool 1B, the lock pin 60 fits into the return groove portion 48, locking the connecting pin 41, just as in the first embodiment (Figures 5(a) to 5(c)).

On the other hand, as shown in Figures 9(a) and 9(b), when the yoke die 30 is improperly installed, if the connecting pin 41 is inserted into the rear engagement pin hole 17B and the engagement pin 50 is guided from the engagement guide groove 44 to the circumferential groove 45, and then the connecting member 40 is turned, the engagement pin 50 passes the bent portion 45c of the circumferential groove 45 and is guided along the reverse inclined groove edge 45b into the reverse guide groove 71. Then, as shown in Figure 9(c), the spring force of the spring 43 urges the connecting member 40 toward the front side (right side in the figure), causing the engagement pin 50 to slide relatively along the reverse guide groove 71 toward the pin tip 41e. The connecting member 40 protrudes toward the front side (right side in the figure) from the head portion 10. As a result, void installation of the connecting pin 41 can be reliably prevented.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the claims.
For example, the circumferential groove 45 does not necessarily have to be provided. After the connecting pin 41 is inserted until the engaging pin 50 reaches the end of the engaging guide groove 44 on the pin head side, the connecting pin 41 may be rotated so that the engaging pin 50 retracts from the inner peripheral surface of the engaging pin hole 17 into the inside of the head portion 10.
The biasing means is not limited to a spring, but may be rubber.

The present invention can be applied to a crimping tool used to crimp and join pipe fittings fitted to the ends of air conditioning pipes or cold water/hot water pipes, for example.

1 Crimping tool 2 Tool body 3 Crimping action part 9 Crimping object 10 Head part 13 Connecting part 14 Connecting plate part 15 Connecting recess 17 Engagement pin hole 20 Press die 30 Yoke die 33 Connecting arm (connected part)
37 Lock pin hole 40 Connecting member 41 Connecting pin 41a Pin head 41e Pin tip 42c Annular gap 43 Spring (biasing means)
44 Engagement guide groove 45 Circumferential groove 45e Inclined groove edge (groove edge)
45b Reverse inclined groove edge 45c Bending portion 46 Lock guide groove 47 Lock groove 48 Return groove portion 50 Engagement pin 60 Lock pin 61 Thread portion 71 Reverse guide groove

Claims (4)

A crimping tool for crimping an object by clamping it between a press die held so as to be movable back and forth in a center portion in a width direction of a head portion at a tip of a tool body, and a yoke die connected to a connecting portion on a side portion of the head portion in the width direction via a connecting member,
An engagement pin hole is formed in the connecting portion, and an engagement pin is provided on an inner peripheral surface of the engagement pin hole,
a lock pin hole communicating with the engagement pin hole is formed in a connected portion of the yoke die that is connected to the connecting portion, and a lock pin is provided on an inner peripheral surface of the lock pin hole,
the connecting member has a connecting pin that is movably passed through the engagement pin hole and the locking pin hole, and a biasing means that biases the connecting pin relative to the head portion in a direction from the pin tip side toward the pin head side along the axial direction of the connecting pin,
an outer peripheral surface of the connecting pin is formed with an engagement guide groove that extends in the axial direction and guides the engagement pin, a lock guide groove that extends parallel to the engagement guide groove and guides the lock pin, and a lock groove that extends from an end of the lock guide groove on the pin head side in the circumferential direction of the connecting pin,
When the engagement pin is at the end of the engagement guide groove on the pin head side, the connecting pin is allowed to rotate,
The rotation causes the lock pin to be engaged with the lock groove, preventing the connecting pin from sliding toward the pin head by the biasing means, while the engagement pin allows the sliding. The crimping tool described in claim 1, characterized in that a circumferential groove is formed on the outer peripheral surface of the connecting pin, extending in the circumferential direction from the end of the engagement guide groove on the pin head side, and the groove edge of the circumferential groove on the pin tip side is inclined toward the engagement guide groove. The crimping tool according to claim 1, characterized in that the outer peripheral surface of the connecting pin is formed with a circumferential groove extending in the circumferential direction from the end of the engagement guide groove on the pin head side, and a reverse guide groove extending in the axial direction from the end of the circumferential groove opposite the engagement guide groove side toward the pin tip side, and the groove edge on the pin tip side in the portion of the circumferential groove on the reverse guide groove side in the extension direction is inclined toward the pin tip side toward the reverse guide groove. The crimping tool described in any one of claims 1 to 3, characterized in that the lock groove has a return groove portion extending toward the pin tip at the end opposite the lock guide groove.