JP2008051684A - Device for determining fastening capability of fastening tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for determining fastening capability of fastening tool capable of precisely determining the fastening capability without receiving effect of sticking between a seal member and a small piston and confirming a vertical fastening torque range by confirming an upper limit value of the fastening torque. <P>SOLUTION: The device includes the small piston 6 receiving a pressure of operating oil S in a sealed container 2, a spring member 7 for biasing the small piston 6 in a direction against the pressure of the operating oil S, a pilot pin 8 moving according to movement of the small piston 6, and an adjustment member 9 adjusting the biasing force of the spring member 7. The device further includes a weak spring 10 for biasing the small piston 6 in a direction separating from the pilot pin 8, wherein a gap 12 is provided between the small piston 6 and a power transmission part 11 of the pilot pin 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tightening tool determination device for a tightening tool that can determine the tightening capability of a tightening tool by a mechanical mechanism under arbitrarily set tightening conditions.

  Conventionally, as a tightening tool used for tightening bolts, nuts, screws, and the like with a predetermined set torque, for example, a hydraulic torque wrench has been widely used.

  By the way, in these tightening tools, the state of the pneumatic power source or power source (battery) as a power source, the state of the tightening tool itself (for example, in the case of a hydraulic torque wrench, the operation enclosed in the torque wrench) Depending on the oil leakage and temperature, etc., tightening may not be performed with a predetermined set torque, resulting in variations in product quality, which has been a factor in reducing product reliability.

  In order to cope with this problem, various devices for controlling or measuring a tightening torque by a tightening tool have been proposed and put into practical use. However, many of these devices are electrically used. The tightening torque is controlled and measured, and is not only expensive, but also requires expertise in its operation and management, and is difficult to handle.

Therefore, the applicant of the present application has proposed a tightening capability determination device for a tightening tool as disclosed in the following patent document.
As shown in FIG. 8, the tightening capability determination device for the tightening tool is filled with a working oil S and has a cylindrical sealed container 2 in which a piston 1 is disposed, and a female screw 2 a formed in the sealed container 2. The pressure of the hydraulic oil S in the sealed container is applied through the male screw 3 that presses the piston 1 and the small hole 4 formed in the sealed container 2 by a rotational tightening operation with a tightening tool. In the tightening capability determination device for a tightening tool comprising the tightening capability determination member 5, the tightening capability determination member 5 includes a small piston 6 that receives the pressure of the hydraulic oil S in the sealed container, and a small piston 6. A spring member 7 that urges in a direction against the pressure of the hydraulic oil S, a pilot pin 8 that moves according to the movement of the small piston 6, and an adjustment member 9 that adjusts the urging force of the spring member 7 are provided. .

This conventional tightening capability determination device for a tightening tool rotates and tightens a male screw 3 screwed into a female screw 2a formed in a sealed container 2 using a tightening tool for determining the tightening capability. The piston 1 is pressed, and the pressure of the hydraulic oil S in the sealed container is applied to the tightening ability determination member 5 through the small hole 4 formed in the sealed container 2.
When the pressure of the hydraulic oil S in the sealed container is applied to the tightening ability determination member 5, the small piston 6 that receives the pressure of the hydraulic oil S biases the spring member in a direction against the pressure of the hydraulic oil S. The pressure of the hydraulic oil S, that is, the magnitude of the torque applied to the male screw 3 by the tightening tool depends on the position of the pilot pin 8 that moves by compressing the small piston 6 and moves according to the movement of the small piston 6. Can be detected.
Then, by adjusting the biasing force of the spring member 7 with the adjusting member 9, the tightening capability of the tightening tool under arbitrarily set tightening conditions can be determined.

By the way, in this conventional tightening tool tightening capacity judging device, since the small piston 6 and the pilot pin 8 are integrated, when it is first used, a seal comprising an O-ring sealing the small piston 6 is used. The fixing force of the material 6a (proportional to the holding time and saturated at a maximum of about 1.5 times the maximum) is multiplied by the spring member 7 for determination, and a phenomenon occurs that the tightening capability determination value increases only for the first time.
In addition, the tightening capability judging device of this tightening tool can confirm that the tool torque is insufficient (no signal is output below the set torque), but cannot confirm the upper limit value of the tightening torque. Could not be prevented.
Japanese Patent Laid-Open No. 2003-340741

  In view of the problems of the conventional tightening capability determination device for a tightening tool, the present invention accurately determines the tightening capability without being affected by the sticking of the sealing material and the small piston, and determines the tightening torque. It is an object of the present invention to provide a tightening capability determination device for a tightening tool capable of confirming an upper and lower tightening torque range by confirming an upper limit value.

  In order to achieve the above object, a tightening capability judging device for a tightening tool according to the first aspect of the present invention includes a cylindrical airtight container filled with hydraulic oil and provided with a piston, and a female screw formed in the airtight container. Tightening capability judgment that the pressure of the hydraulic oil in the sealed container is applied through the male screw that presses the piston and the small hole formed in the sealed container by rotating and tightening with a tightening tool In a tightening capacity determination device for a tightening tool composed of a member, the tightening capacity determination member biases the small piston that receives the pressure of the hydraulic oil in the sealed container and the small piston in a direction that resists the pressure of the hydraulic oil. A spring member that moves in response to the movement of the small piston, an adjustment member that adjusts the biasing force of the spring member, and a weak spring that biases the small piston in a direction away from the pilot pin. Pi Characterized in that a gap between the tons and the pilot pin or a power transmission unit.

  In addition, the tightening ability judging device for a tightening tool according to the second aspect of the present invention is filled with hydraulic oil, screwed into a cylindrical sealed container provided with a piston, and a female screw formed in the sealed container. A fastening comprising a male screw for pressing the piston by a rotary fastening operation with an attached tool, and a fastening capability judging member for applying hydraulic oil pressure in the sealed container through a small hole formed in the sealed container. In the tightening capacity determination device for an attached tool, the tightening capacity determination member includes a small piston that receives the pressure of the hydraulic oil in the sealed container, and a lower limit torque spring that biases the small piston in a direction that resists the pressure of the hydraulic oil. And a rod-shaped pilot pin that moves in response to the movement of the small piston, and an adjusting member that adjusts the biasing force of the spring member, and the small piston is brought to the pressure of the hydraulic oil from the position where it is pushed against the lower limit torque spring. Resist An upper limit torque spring that biases in the direction, and a pilot pin return mechanism that releases the pilot pin and returns it from the moving position when the small piston moves as required against the upper limit torque spring. .

  In this case, the pilot pin return mechanism includes a reset spring that biases the pilot pin toward the return side, a groove formed in the pilot pin, a latch ball that is detachably provided in the groove, and a slide on the pilot pin. A slide base that holds the latch ball in the through hole formed in the cylinder wall and transmits the movement of the small piston to the pilot pin via the latch ball, and a slidable outer fit to the slide base And a retainer for engaging the latch ball with the groove of the pilot pin at the position where the through hole is closed, and the retainer is urged toward the moving side to support the position where the through hole is closed, and the slide base has an upper limit torque. When moved beyond the specified position against the spring, the retainer can move to a position where it comes into contact with the fixed member and opens the through hole. .

  Moreover, while forming the window part which visually recognizes a piston in the surrounding wall of a cylindrical airtight container, the identification mark which differs in an axial direction position can be provided in a piston surrounding surface.

  According to the tightening capability judging device for a tightening tool of the first invention, a weak spring is provided so that the small piston can slide against the resistance of the sealing material, and the small piston and the pilot pin or its power transmission portion are connected. Since a gap is provided between them, at the time of initial tightening, after the small piston passes through this gap and is fixed to the sealing material, the small piston can come into contact with the pilot pin or its power transmission part. Thereby, it is possible to accurately determine the tightening ability without being affected by the sticking by the sealing material.

  Further, according to the tightening capability determination device for a tightening tool of the second aspect of the present invention, the upper limit torque spring that biases the small piston in the direction against the pressure of the hydraulic oil from the position where it is pushed against the lower limit torque spring. And a pilot pin return mechanism that releases the pilot pin and returns it from the moving position when the small piston moves against the upper limit torque spring, so check the upper limit value of the tightening torque, The tightening torque range can be confirmed, thereby preventing the bolt from being broken due to overtightening or loosening due to insufficient tightening.

  In this case, the pilot pin return mechanism includes a reset spring that biases the pilot pin toward the return side, a groove formed in the pilot pin, a latch ball that is detachably provided in the groove, and slides on the pilot pin. A slide base that holds the latch ball in the through-hole formed in the cylinder wall and transmits the movement of the small piston to the pilot pin via the latch ball, and a slidable outer fit on the slide base And a retainer that engages the latch ball with the groove of the pilot pin at the position where the through hole is closed, and the retainer is urged toward the moving side to support the position where the through hole is closed, and the slide base is the upper limit torque spring. If the retainer moves to a position that abuts against the fixed side member and opens the through hole when it moves beyond the specified position against Reliable structure, the upper limit of the tightening torque can be checked reliably.

  In addition, a piston for visually recognizing the piston is formed on the peripheral wall of the cylindrical airtight container, and a piston having a different initial position depending on the amount of hydraulic oil is used by providing an identification mark that differs in the axial position on the peripheral surface of the piston. Then, the amount of hydraulic oil can be confirmed by visually recognizing the identification mark of the piston.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a tightening capability determination device for a tightening tool according to the present invention will be described below with reference to the drawings.

1 to 4 show a first embodiment of a tightening capability determination device for a tightening tool according to the present invention.
The tightening capability judging device of this tightening tool is filled with hydraulic oil S and screwed into a cylindrical sealed container 2 provided with a piston 1 and a female screw 2a formed in the sealed container 2 for tightening. Tightening capability determination in which the pressure of the hydraulic oil S in the sealed container 2 is applied through the male screw 3 that presses the piston 1 and the small hole 4 formed in the sealed container 2 by a rotary tightening operation using a tool. It consists of member 5.

  The tightening ability determination member 5 includes a small piston 6 that receives the pressure of the hydraulic oil S in the sealed container 2, a spring member 7 that urges the small piston 6 in a direction against the pressure of the hydraulic oil S, A pilot pin 8 that moves in accordance with the movement of the piston 6 and an adjustment member 9 that adjusts the biasing force of the spring member 7 and a weak spring 10 that biases the small piston 6 in a direction away from the pilot pin 8. A gap 12 is provided between the small piston 6 and the power transmission portion 11 of the pilot pin 8.

  A band-shaped display portion 8a is formed at the tip of the pilot pin 8 slidably disposed in the main body 13, and the display portion 8a is exposed from the main body 13 to increase the tightening capability of the tightening tool. Judgment is made.

As shown in FIG. 4, a window portion 2 b for visually recognizing the piston 1 is formed on the peripheral wall of the cylindrical airtight container 2, and the color of the peripheral surface of the piston 1 is different depending on the axial position. A mark 1a is provided.
Thus, for example, the periphery of the piston 1 is color-coded in the axial direction, the piston 1 whose initial position is different depending on the amount of the hydraulic oil S is used, and the hydraulic oil S is identified by visually recognizing the identification mark 1a of the piston 1. The amount of can be confirmed.

  The tightening capability determination device for a tightening tool configured as described above performs a rotational tightening operation on the male screw 3 screwed into the female screw 2a formed on the sealed container 2, using the tightening tool for determining the tightening capability. Thus, the piston 1 is pressed through the steel ball 1 b so that the pressure of the hydraulic oil S in the sealed container 2 is applied to the small piston 6 of the tightening ability determination member 5.

As described above, when the pressure of the hydraulic oil S in the sealed container 2 is applied to the tightening ability determination member 5, the small piston 6 that receives the pressure of the hydraulic oil S is biased in a direction against the pressure of the hydraulic oil S. The spring member 7 to be compressed is moved.
Then, depending on the position of the pilot pin 8 that moves according to the movement of the small piston 6, specifically, whether or not the strip-shaped display portion 8 a formed on the pilot pin 8 is exposed from the main body 13, the hydraulic oil The magnitude of the pressure of S, that is, the magnitude of the torque applied to the male screw 3 by the tightening tool can be detected.

At this time, as shown in FIG. 3, the tightening capability judging device for the tightening tool of the present embodiment uses a weak spring 10 that can slide the small piston 6 against the resistance of the sealing material 6a made of an O-ring. Since the air gap 12 is provided between the small piston 6 and the power transmission portion 11 of the pilot pin 8, the small piston 6 passes through the air gap 12 and is not fixed to the sealing material 6a at the time of initial tightening. After that, the small piston 6 can come into contact with the power transmission portion 11 of the pilot pin 8, so that the tightening ability can be accurately determined without being affected by the sticking by the sealing material 6a.
3A shows a state before tightening, and FIG. 3B shows a state where the tightening torque has overcome the multiplication of the force of the weak spring 10 and the fixing force of the sealing material 6a. FIG. 4C shows a state in which the tightening torque is operated by overcoming the addition of the force of the weak spring 10 and the set spring force.

5 to 7 show a second embodiment of the tightening capability determination device for a tightening tool according to the present invention.
The tightening capability judging device of this tightening tool is filled with hydraulic oil S and screwed into a cylindrical sealed container 2 provided with a piston 1 and a female screw 2a formed in the sealed container 2 for tightening. Tightening capability determination in which the pressure of the hydraulic oil S in the sealed container 2 is applied through the male screw 3 that presses the piston 1 and the small hole 4 formed in the sealed container 2 by a rotary tightening operation using a tool. And a member 5.

The tightening capacity determination member 5 includes a small piston 6 that receives the pressure of the hydraulic oil S in the sealed container 2, a lower limit torque spring 14 that biases the small piston 6 in a direction against the pressure of the hydraulic oil S, and a small piston. 6 is provided with a rod-like pilot pin 8 that moves in accordance with the movement of 6 and an adjustment member 9a that adjusts the urging force of the lower limit torque spring 14.
Further, an upper limit torque spring 15 that urges the small piston 6 in a direction against the pressure of the hydraulic oil S from a position where it is pushed against the lower limit torque spring 14, and a small piston against the upper limit torque spring 15. A pilot pin return mechanism 16 that releases the pilot pin 8 to return from the moving position when the required movement of 6 is provided, and an adjustment member 9 b that adjusts the urging force of the upper limit torque spring 15.

The pilot pin return mechanism 16 includes a reset spring 17 that biases the pilot pin 8 toward the return side, a circumferential groove 18 formed in the pilot pin 8, and a latch ball 19 that is detachably provided in the groove 18. And a slide that slidably fits on the pilot pin 8, holds the latch ball 19 in the through hole 20 a formed in the cylindrical wall, and transmits the movement of the small piston 6 to the pilot pin 8 via the latch ball 19. A base 20 and a retainer 21 that slidably fits on the slide base 20 and engages the latch ball 19 with the groove 18 of the pilot pin 8 at a position that closes the through hole 20a are provided.
The retainer 21 is urged toward the moving side by the reset spring 17 to support the position where the through hole 20a is closed, and when the slide base 20 moves beyond the specified position against the upper limit torque spring 15, the retainer 21 is moved. 21 abuts against a part of the main body 13 so as to retreat to a position where the through hole 20a is opened.

Next, the operation of the tightening capability determination device for the tightening tool of this embodiment will be described.
Before the set tightening torque, as shown in FIG. 7A, the force received by the small piston 6 by the lower limit torque spring 14 is suppressed via the slide base 20 and the power transmission portion 11 of the pilot pin 8. Yes.
In this state, the force of the upper limit torque spring 15 is not involved.

Next, when tightening within the set tightening torque range, as shown in FIG. 7B, the force received by the small piston 6 overcomes the lower limit torque spring 14 and reaches a position where it is suppressed by the upper limit torque spring 15. The slide base 20 moves.
At this time, the slide base 20 simultaneously moves the pilot pin 8 via the latch ball 19 and displays the display portion 8a of the pilot pin 8 as a tightening OK confirmation mark so as to protrude from the main body 13.

On the other hand, if the tightening is performed exceeding the upper limit of the set tightening torque, the force received by the small piston 6 via the slide base 20 and the spring receiving member 15a as shown in FIGS. Overcomes the upper and lower torque springs 14 and 15, and the slide base 20 further moves.
At this time, in the tightening within the set tightening torque range described above, the slide base 20 and the retainer 21 have moved together. However, if tightening is performed exceeding the upper limit of the set tightening torque, FIG. ), The retainer 21 stops moving at the position where the main body 13 comes into contact with the end.
When the slide base 20 further moves, as shown in FIG. 7D, the retainer 21 is relatively moved rearward, and the latch ball 19 held by the retainer 21 is increased in diameter. The pilot pin 8 is instantaneously returned to the small piston 6 side by the force of the reset spring 17.
As a result, the display portion 8a (tightening OK confirmation mark) of the pilot pin 8 is closed, indicating that tightening exceeding the upper limit of the set tightening torque has been performed.

On the other hand, after the tightening tool is loosened, as shown in FIG. 7 (e), the small piston 6 whose internal pressure is released returns to the position before tightening via the slide base 20 by the lower limit torque spring 14.
The slide base 20 and the retainer 21 move integrally through the latch ball 19 until returning, but the latch ball 19 approaches the position of the pilot pin groove 18 by the slide base 20 that slides against the pilot pin 8. The latch ball 19 falls into the groove 18 of the pilot pin 8 by being pushed by the retainer 21 biased by the reset spring 17.
As a result, as shown in FIG. 7A, the retainer 21 is instantaneously reset to the position before the set tightening torque.
The pilot pin 8 is positioned by the retaining ring 22 that contacts the main body 13 and the reset spring 17 of the pilot pin 8 in a state before the set tightening torque.

  Thus, according to the tightening ability determination device for a tightening tool of the present embodiment, the upper limit for biasing the small piston 6 in the direction against the pressure of the hydraulic oil S from the position pushed against the lower limit torque spring 14. Since it includes a torque spring 15 and a pilot pin return mechanism 16 that releases the pilot pin 8 and returns it from the moving position when the small piston 6 moves against the upper limit torque spring 15, the upper limit of the tightening torque is provided. The value can be confirmed, and the upper and lower tightening torque ranges can be confirmed, thereby preventing the bolt from being broken due to overtightening or loosening of the bolt due to insufficient tightening.

  The pilot pin return mechanism 16 includes a reset spring 17 that biases the pilot pin 8 toward the return side, a groove 18 formed in the pilot pin 8, and a latch ball 19 that is detachably provided in the groove 18. A slide base that slidably fits on the pilot pin 8, holds the latch ball 19 in a through hole 20 a formed in the cylindrical wall, and transmits the movement of the small piston 6 to the pilot pin 8 via the latch ball 19. 20 and a retainer 21 that is slidably fitted to the slide base 20 and engages the latch ball 19 with the groove 18 of the pilot pin 8 at a position where the through hole 20a is closed, and the retainer 21 is attached to the moving side. When the slide base 20 moves beyond the specified position against the upper limit torque spring 15, while supporting the position where the through hole 20a is obstructed. By retainer 21 to move to a position to open the contact through hole 20a to the stationary member, by a simple and reliable structure, the upper limit of the tightening torque can be checked reliably.

  As mentioned above, although the clamping capability determination apparatus of the clamping tool of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, The structure described in the Example The configuration can be changed as appropriate without departing from the spirit of the invention, for example, by appropriately combining the two.

  The tightening capability determination device for a tightening tool of the present invention accurately determines the tightening capability without being affected by the sticking by the oil seal material, and confirms the upper limit value of the tightening torque, thereby Since it has the characteristic of confirming the torque range, it can be used widely and suitably for applications of a tightening capability determination device for tightening tools that require precision.

It is sectional drawing which shows 1st Example of the clamping capability determination apparatus of the clamping tool of this invention. It is sectional drawing which shows the clamping capability determination member of the Example. The operation of the tightening ability determining member is shown, (a) is a cross-sectional view showing a state before tightening, (b) is a state in which the tightening torque is operated by overcoming the multiplication of the weak spring force and the fixing force of the sealing material. (C) is sectional drawing which shows the state which the tightening torque overcomes and adds to weak spring force and setting spring force. The embodiment which provided the window part in the cylinder-shaped airtight container is shown, (a) is sectional drawing which shows the state without hydraulic fluid, (b) is sectional drawing which shows the state with little hydraulic fluid, (c) is hydraulic fluid It is sectional drawing which shows the state in which the quantity of is normal. The 2nd Example of the clamping capability determination apparatus of the clamping tool of this invention is shown, (a) is a top view, (b) is sectional drawing. It is sectional drawing which shows the clamping capability determination member of the Example. The operation of the tightening ability determination member is shown, (a) is a cross-sectional view showing a state before tightening, (b) is a cross-sectional view showing a state of tightening within a set tightening torque range, and (c) to (d). Is a sectional view showing a state of tightening exceeding the upper limit of the set tightening torque, and (e) is a sectional view showing a state after the tightening tool is loosened. It is sectional drawing which shows the clamping capability determination apparatus of the conventional clamping tool.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 1a Identification mark 1b Steel ball 2 Sealed container 2a Female screw 2b Window part 3 Male screw 4 Small hole 5 Tightening ability judgment member 6 Small piston 6a Sealing material 7 Spring member 8 Pilot pin 8a Display part 9 Adjustment member 10 Weak spring 11 Power Transmission portion 12 Gap 13 Body 14 Lower limit torque spring 15 Upper limit torque spring 15a Spring receiving member 16 Pilot pin return mechanism 17 Reset spring 18 Pilot pin groove 19 Latch ball 20 Slide base 20a Through hole 21 Retainer 22 Retaining ring

Claims (4)

  A cylinder-shaped sealed container filled with hydraulic oil inside, and a male screw that is screwed into a female screw formed in the sealed container, and that presses the piston by a rotary tightening operation with a tightening tool; In a tightening capacity judging device for a tightening tool comprising a tightening capacity judging member that applies hydraulic pressure in the sealed container through a small hole formed in the sealed container, the tightening ability judging member is sealed. A small piston that receives the pressure of the hydraulic oil in the container, a spring member that biases the small piston in a direction against the pressure of the hydraulic oil, a pilot pin that moves according to the movement of the small piston, and a biasing force of the spring member An adjustment member for adjusting, a weak spring for urging the small piston in a direction away from the pilot pin, and a gap between the small piston and the pilot pin or its power transmission unit. Tightening capacity determination device of the tightening tool to butterflies.   A cylinder-shaped sealed container filled with hydraulic oil inside, and a male screw that is screwed into a female screw formed in the sealed container, and that presses the piston by a rotary tightening operation with a tightening tool; In a tightening capacity judging device for a tightening tool comprising a tightening capacity judging member that applies hydraulic pressure in the sealed container through a small hole formed in the sealed container, the tightening ability judging member is sealed. A small piston that receives the pressure of the hydraulic oil in the container, a lower limit torque spring that urges the small piston in a direction against the pressure of the hydraulic oil, a rod-like pilot pin that moves according to the movement of the small piston, and a spring member And an upper limit torque spring for biasing the small piston in a direction against the pressure of the hydraulic oil from a position where it is pushed against the lower limit torque spring, and an upper limit torque spring. Clamping capability determination device of the tightening tool, characterized in that a pilot pin returning mechanism for returning the moving position to release the pilot pin when the small piston is required moved against the.   The pilot pin return mechanism includes a reset spring that urges the pilot pin toward the return side, a groove formed in the pilot pin, a latch ball that is detachably provided in the groove, and a slidable outer contact with the pilot pin. A slide base that holds the latch ball in the through hole formed in the cylindrical wall and transmits the movement of the small piston to the pilot pin via the latch ball, and a slide base that is slidably fitted on the slide base. And a retainer for engaging the latch ball with the groove of the pilot pin at the position where it is closed, and the retainer is urged toward the moving side to support the position where the through hole is closed, and the slide base resists the upper limit torque spring. The retainer moves to a position where the retainer comes into contact with the stationary member and opens the through hole when moved beyond the specified position. Tightening capacity determination device of the tightening tool.   4. The tightening according to claim 1, wherein a window portion for visually recognizing the piston is formed on a peripheral wall of the cylindrical airtight container, and an identification mark which is different in an axial position is provided on the peripheral surface of the piston. Tool tightening ability judgment device.

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