JP2011230223A - Control device of fastening force of hydraulic torque wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of fastening force of a hydraulic torque wrench capable of measuring the fastening force of a fastening member by a simple mechanism by using an ultrasonic probe, and capable of also eliminating erroneous installation of the fastening member such as a bolt.SOLUTION: This control device of the fastening force of the hydraulic torque wrench is provided so that the ultrasonic probe Se1 is arranged in a tip part of a main shaft S for generating impact torque via an impact torque generating device T rotatingly driven by a motor R, and includes: a length measuring means of a fastening member for measuring the length of the fastening member by measuring a propagation time of an echo from a tip surface of the fastening member by propagating an ultrasonic wave to the fastening member from the ultrasonic probe Se1 arranged in the tip part of the main shaft S; a fastening force measuring means for measuring the fastening force of the fastening member in real time in fastening work from the length of the fastening member measured by the length measuring means of the fastening member and the initial length of the fastening member measured before fastening; and a motor control means for finishing the fastening work by stopping the motor R when the fastening force of the fastening member measured by the fastening force measuring means reaches a predetermined value.

Description

  The present invention relates to a control device for a tightening force of a hydraulic torque wrench, and more particularly, a control of a tightening force of a hydraulic torque wrench configured to measure a tightening force of a fastening member using an ultrasonic probe. It relates to the device.

  Conventionally, as a hydraulic torque wrench, a hydraulic torque wrench using a hydraulic impact torque generator with low noise and vibration has been developed and put to practical use (for example, see Patent Document 1).

4 to 5 show an example of this hydraulic torque wrench, and the impact torque generator T of this hydraulic torque wrench W fills the liner chamber La formed in the liner L with hydraulic oil. Then, a blade insertion groove Sa and a spring insertion hole Sb are provided on the main shaft S coaxially inserted into the liner L, and the blade Bl is inserted into the blade insertion groove Sa and the spring Sp is inserted into the spring insertion hole Sb. B1 is always urged by the spring Sp in the outer peripheral direction of the main shaft and brought into contact with the inner peripheral surface of the liner chamber La, and a seal surface is formed on the outer peripheral surface of the main shaft S and the inner peripheral surface of the liner chamber La.
When the liner L is rotated by the air motor R, the seal surface formed on the inner peripheral surface of the liner chamber La matches the seal surface formed on the outer peripheral surface of the main shaft S and the blades Bl. A striking torque is generated.

  In addition, as a hydraulic torque wrench, in addition to Patent Document 2 and Patent Document 3 previously proposed by the present applicant in order to solve problems such as wear of members of a conventional hydraulic torque wrench and breakage of a spring, etc. There is a description.

  Among these, the hydraulic torque wrench described in Patent Document 2 uses an air motor as a drive source, as shown in FIGS. 6 to 10. The main shaft 3 and the main shaft 3 are connected to the main shaft 3. The cam 4 is inserted so as to be slidable in the axial direction without rotating, the cam grooves 41a and 41b are formed on the outer peripheral surface, and the oil guide holes 42a and 42b penetrating in the axial direction are formed inside, and the main shaft 3 And the cam 4 of the cam 4 which protrudes on the inner peripheral surface of the cylinder C and the cylinder C which forms the oil chambers A and B filled with the hydraulic oil with the cam 4 interposed therebetween. Pins 81 and 82 inserted into the grooves 41a and 41b, a drive shaft 23 connected to a drive source (not shown) for rotationally driving the cylinder C, and the cam 4 according to the relative rotation angle of the cam 4 and the cylinder C Selectively close the oil guide holes 42a, 42b formed in The Rukoto, and a check valve 5 for blocking a flow of hydraulic fluid between the sandwiched therebetween formed oil chambers A, B of the cam 4.

  In this case, as shown in FIG. 6, the cylinder C is fitted to the outer casing 1 that constitutes one end face wall 11 and the cylinder portion 12, and the other end face wall 21 and cylinder portion 22. The inner casing 2 constituting the drive shaft 23 and the opening end of the cylinder portion 12 of the outer casing 1 are screwed together to fix the inner casing 2 fitted to the outer casing 1 and integrate them. The fixing member 9 is constituted.

  Further, as shown in FIG. 6, the main shaft 3 in which the base end portion is accommodated in the cylinder C has a base hole 31a formed in the end wall 21 of the inner casing 2 via a ball bearing 24a. In order to insert the cam 4 so as to be slidable in the axial direction without rotating with respect to the main shaft 3, the cross-sectional shape of the shaft 31 of this portion is, for example, a polygonal shape, a spline shape, In this example, it is formed in a hexagonal shape, and further, a flange portion 33 is formed on the tip side to prevent it from coming off, and the tip side penetrates and extends through the end face wall 11 of the outer casing 1.

  The cam 4 that is slidably fitted in the axial direction without rotating with respect to the main shaft 3 slides in the axial direction without rotating the cam 4 with respect to the main shaft 3, as shown in FIGS. In order to insert it in a possible manner, the cross-sectional shape of the hole 43 in this portion is formed in, for example, a hexagonal shape corresponding to the main shaft 3.

The cam grooves 41a and 41b formed on the outer peripheral surface of the cam 4 are the inner casings of the cylinder C that are fitted into the cam grooves 41a and 41b when the cylinder C is rotationally driven through the drive shaft 23 connected to the drive source. For example, an annular spiral is used so that the cam 4 can be slid in the axial direction without rotating with respect to the main shaft 3 by the action of the pins 81 and 82 projecting from the inner peripheral surface of the second cylinder portion 22. Form into shape. By the way, although two cam grooves 41a and 41b are formed in this example, the number of cam grooves is not limited to this, and can be one or more than three. When a plurality of cam grooves 41a and 41b are formed as in this example, pins that protrude from the inner peripheral surface of the cylinder portion 22 of the inner casing 2 of the cylinder C and are inserted into the respective cam grooves are inserted. 81 and 82 are projected so as to have an equal angular interval (180 ° in this example).
Thus, by providing the plurality of cam grooves 41a and 41b and the pins 81 and 82, a large rotational driving force can be smoothly transmitted from the cylinder C to the cam 4 via the pins 81 and 82. The impact torque can be stably generated on the main shaft 3 into which the shaft 4 is inserted.

  Also, the oil guide holes 42a and 42b penetrating in the axial direction inside the cam 4 are oils formed so as to sandwich the cam 4 when the cam 4 slides in the axial direction without rotating with respect to the main shaft 3. Although it is not particularly limited so as to have a sufficient capacity to smoothly distribute the hydraulic oil between the chambers A and B, in this example, it is configured with two through holes. I have to.

  By selectively closing the oil guide holes 42a and 42b formed in the cam 4 according to the relative rotation angle of the cam 4 and the cylinder C, the operation between the oil chambers A and B formed with the cam 4 interposed therebetween. The check valve 5 that shuts off the oil flow is always arranged in one oil chamber A so as to be urged by the spring 6 so as to abut one end surface of the cam 4, and is driven by the cylinder C. And rotate it.

  As shown in FIG. 9, the check valve 5 includes a disc-shaped main body portion 51 that is in contact with one end surface of the cam 4, and an annular portion 53 that extends along the inner peripheral surface of the cylinder portion 22 of the inner casing 2 of the cylinder C. It consists of.

  The main body 51 is formed with curved long holes 52a and 52b that are electrically connected to the oil guide holes 42a and 42b formed in the cam 4 and allow the hydraulic oil to flow between the oil chambers A and B. The oil guide holes 42a and 42b formed in the cam 4 are closed by a portion where the hole between the long holes 52a and 52b is not formed. Depending on the position and number of the long holes 52a and 52b formed in the main body 51, the number and magnitude of impact torque generated while the cam 4 and the cylinder C are rotated by 360 ° are determined.

  By forming the long holes 52a and 52b at the positions shown in this example, the oil guide holes 42a and 42b formed in the cam 4 by the check valve 5 each time the cam 4 and the cylinder C rotate 360 ° relatively. And the flow of hydraulic oil between the oil chambers A and B formed with the cam 4 interposed therebetween can be shut off, so that each time the cam 4 and the cylinder C rotate 360 ° relatively. In addition, a large impact torque can be generated once by utilizing the inertia of the cylinder C.

  Further, the cylinder portion 12 of the outer casing 1 of the cylinder C and the cylinder portion 22 of the inner casing 2 are formed with oil guide passages 15 and 25 connecting the oil chambers A and B formed with the cam 4 interposed therebetween, The output adjusting mechanism 13 that can arbitrarily adjust the magnitude of the impact torque generated by restricting the flow rate of the hydraulic oil flowing through the oil guide passages 15 and 25 is screwed into the end face wall 11 of the outer casing 1. It arrange | positions by doing. As a result, the output adjusting mechanism 13 is adjusted to limit the flow rate of the hydraulic oil flowing through the oil guide passage 25 connecting the oil chambers A and B formed with the cam 4 sandwiched between the cylinders C. The magnitude of the hitting torque to be generated can be easily adjusted. Specifically, as the flow rate of the working oil flowing through the oil guide passage 25 is reduced by adjusting the output adjusting mechanism 13, The magnitude can be increased, and conversely, the greater the flow rate of the working oil flowing through the oil guide path 25, the smaller the magnitude of the impact torque that can be generated.

  Further, the annular portion 53 is formed with a long hole 55 into which a pin 54 projecting from the inner peripheral surface of the cylinder portion 22 of the inner casing 2 of the cylinder C is inserted, whereby the check valve 5 is connected to the cylinder C. While being driven and rotated, the cam 4 is driven to slide while being in contact with one end surface of the cam 4.

  Further, a plug 14 for injecting hydraulic oil into the oil chambers A and B is disposed on the end surface wall 11 of the outer casing 1 by screwing or the like.

  Also, seals such as O-rings that prevent leakage of hydraulic fluid are provided between the outer casing 1 and the inner casing 2 of the cylinder C, between the outer casing 1 and the main shaft 3 of the cylinder C, the output adjusting mechanism 13, the plug 14, and the like. The members 71, 72, 73, 74 are arranged.

  Hereinafter, the operation of the impact torque generator of the hydraulic torque wrench will be described with reference to FIG. First, the cylinder C is rotationally driven (rotated clockwise as viewed from the drive shaft 23 side) via a drive shaft 23 connected with an air motor as a drive source.

  When the cylinder C is rotationally driven, the inside of the impact torque generating device is as shown in FIG. 10 (1) → (2) → (3) → (4) → (5) → (6) → (1). It changes as follows. FIG. 10 (1) shows a state in which no impact torque is generated on the main shaft 3. From this, the state in which the cylinder C and the cam 4 are rotated by 60 degrees relative to each other in order (referenced to the cam 4) is shown in FIG. 2), (3) (state in which impact torque is generated in the main shaft 3), (4), (5), and (6).

  First, as shown in FIG. 10 (1), when the oil guide holes 42a and 42b formed in the cam 4 and the long holes 52a and 52b formed in the check valve 5 are electrically connected, the oil chambers A and B Therefore, the cam 4 in which the pins 81 and 82 projecting from the inner peripheral surface of the cylinder C are inserted and inserted freely in the axial direction without rotating with respect to the main shaft 3. The cam 4 can be slid from the right side to the left side when viewed from the front (in FIG. 6), and the hydraulic oil flows from the oil chamber B to the oil chamber A. In this state, Since the cylinder C and the cam 4 are not restrained, no hitting torque is generated.

  When the cylinder C is further rotated from this state, as shown in FIG. 10 (2), the oil guide holes 42a and 42b formed in the cam 4 and the long holes 52a and 52b formed in the check valve 5 are electrically connected. (The same state as FIG. 10 (1) in which no impact torque is generated. However, the cam 4 slides from the left side to the right side in front view (in FIG. 6). The oil guide holes 42a and 42b formed in the cam 4 and the long holes 52a and 52b formed in the check valve 5 are electrically connected as shown in FIG. No state.

  In the state shown in FIG. 10 (3), the cam 4 slides from the left side to the right side when viewed from the front (in FIG. 6), so that the oil chamber A in the sliding direction is at a high pressure. The oil chamber B in the opposite direction becomes a low pressure. Then, the flow of hydraulic oil from the high-pressure oil chamber A to the low-pressure oil chamber B is interrupted. In this state, when the cylinder C is further driven to rotate and the cam 4 is slid in the axial direction, the oil Chamber A is at a higher pressure and oil chamber B is at a lower pressure. At this time, the pins 81 and 82 projecting from the inner peripheral surface of the cylinder C are strongly brought into contact with the side surfaces of the cam grooves 41a and 41b formed on the outer peripheral surface of the cam 4 on the high pressure oil chamber A side. However, since the flow of the hydraulic oil from the high pressure oil chamber A to the low pressure oil chamber B is blocked, the cam 4 is prevented from sliding, so that the side surfaces of the cam grooves 41a and 41b and the pins 81 and 82 Thus, a large frictional force is generated and the cylinder C and the cam 4 are restrained. Thereby, a rotational driving force can be transmitted from the cylinder C to the cam 4 via the pins 81 and 82, and an impact torque can be generated in the main shaft 3 into which the cam 4 is inserted.

  When the cylinder C is further rotated from this state, the oil guide holes 42a and 42b formed in the cam 4 and the check valve 5 are formed again as shown in FIGS. 10 (4) and 10 (5). State in which the long holes 52a and 52b are in conduction (the same state as FIG. 10 (1) in which no impact torque is generated. However, in FIG. 10 (4), the cam 4 is viewed from the front (in FIG. 6). The hydraulic oil flows from the oil chamber A to the oil chamber B from the left side to the right side. On the other hand, in FIG. 10 (5), the cam 4 is viewed from the front (in FIG. 6) from the right side. The hydraulic oil slides to the left and flows from the oil chamber B to the oil chamber A.), and as shown in FIG. 10 (6), oil guide holes 42a and 42b formed in the cam 4, and check valves 5, the long holes 52a and 52b formed in the state 5 are not conductive.

  In the state shown in FIG. 10 (6), the cam 4 slides from the right side to the left side when viewed from the front (in FIG. 6), so that the oil chamber B in the sliding direction is at a high pressure. The oil chamber A in the opposite direction becomes a low pressure. However, when the oil chamber B reaches a high pressure, unlike the state shown in FIG. 10 (3), the hydraulic pressure of the hydraulic oil in the oil chamber B passes through the oil guide holes 42 a and 42 b formed in the cam 4. The check valve 5 acting on the check valve 5 and resisting the urging force of the spring 6 is retracted so that the check valve 5 that is in contact with one end surface of the cam 4 is retracted, and the hydraulic oil from the high-pressure oil chamber B to the low-pressure oil chamber A Since the circulation is allowed, the cam 4 in which the pins 81 and 82 projecting from the inner peripheral surface of the cylinder C are inserted can be freely slid in the axial direction without rotating with respect to the main shaft 3. As a result, the cylinder C and the cam 4 are not restrained, so that no striking torque is generated.

  When the cylinder C is further rotated from this state, as shown in FIG. 10 (1), the oil guide holes 42a and 42b formed in the cam 4 and the long holes 52a and 52b formed in the check valve 5 are again formed. It is in a conductive state (a state where no hitting torque is generated).

  Thus, according to the impact torque generating device of this hydraulic torque wrench, the oil guide hole formed in the cam 4 by the check valve 5 substantially every time the cylinder C and the cam 4 rotate 360 ° relatively. 42a and 42b can be closed, and the flow of hydraulic oil between oil chambers A and B formed with the cam 4 interposed therebetween can be blocked, so that the cam 4 and the cylinder C are relatively 360 °. Each time it rotates, a large impact torque can be generated once using the inertia of the cylinder C.

  Further, when the air motor as the drive source is rotated in the reverse direction (left rotation as viewed from the drive shaft 23 side), the inside of the impact torque generating device is as shown in FIGS. 10 (1) → (6) → (5). → (4) → (3) → (2) → (1)... In this case, in the state of FIG. 10 (6), it is possible to generate a striking torque in the opposite direction to the main shaft 3.

  For example, by changing the position and number of the long holes 52a and 52b formed in the main body 51, the impact torque is generated a plurality of times while the cam 4 and the cylinder C relatively rotate 360 °. In addition to an air motor, an electric motor can be used as a drive source.

  By the way, the conventional hydraulic torque wrench is provided with an output adjustment mechanism so that the magnitude of the generated impact torque can be arbitrarily adjusted. This output adjustment mechanism limits the flow rate of hydraulic oil. It adjusts the magnitude of the impact torque generated by this, and does not directly measure the tightening force of a fastening member such as a bolt, so the tightening force of the fastening member could not be confirmed.

On the other hand, as a measuring device for directly measuring the fastening force of a fastening member such as a bolt, a measuring device that measures the fastening force of the fastening member using an ultrasonic probe Has been put into practical use (see, for example, Patent Documents 4 and 5).
However, this measuring device is generally configured separately from the wrench as described in Patent Document 4, and when configured integrally with the wrench, the rotating spindle is rotated. Since it is necessary to derive an electrically connected cable from the ultrasonic probe disposed at the tip, the electrical connection mechanism between the rotating member (main shaft) and the stationary member is particularly complicated, and the patent As described in Document 5, there is a problem that the socket main body and the measuring socket are increased in size and it is difficult to incorporate the measuring device into a hand-held hydraulic torque wrench.
Further, the conventional measuring apparatus has a problem that it cannot be excluded when there is a wrong assembly of fastening members such as bolts, for example, bolts having different lengths.

Japanese Utility Model Publication No. 1-29012 Japanese Patent No. 3361794 Japanese Patent No. 2804904 JP 2004-114182 A JP 2000-74764 A

  In view of the problems of the conventional hydraulic torque wrench described above, the present invention can measure the tightening force of a fastening member with a simple mechanism using an ultrasonic probe, as well as a bolt or the like. It is an object of the present invention to provide a tightening force control device for a hydraulic torque wrench that can eliminate the erroneous assembly of the fastening members.

  In order to achieve the above object, the tightening force control device for a hydraulic torque wrench according to the present invention is more than the tip of a main shaft that generates a striking torque via a striking torque generator that is rotationally driven by a motor. In an apparatus for controlling the tightening force of a hydraulic torque wrench in which an acoustic probe is disposed, an ultrasonic wave is propagated from an ultrasonic probe disposed at a tip of a main shaft to a fastening member, and the fastening member Fastening member length measuring means for measuring the length of the fastening member by measuring the propagation time of the echo from the front end surface of the fastening member, the fastening member length measured by the fastening member length measuring means, and the fastening The fastening force measuring means for measuring the fastening force of the fastening member in real time during the fastening operation from the initial length of the fastening member measured before, and the fastening force of the fastening member measured by the fastening force measuring means are predetermined. When the value of Characterized by comprising a motor control means for terminating the fastening operation to stop the motor.

  In this case, the length of the fastening member when the fastening force of the fastening member reaches a predetermined value is calculated from the initial length of the fastening member measured before fastening and measured by the fastening member length measuring means. By comparing with the length of the fastening member thus made, it can be determined that the fastening force of the fastening member has reached a predetermined value.

  In addition, storage means for storing in advance the initial length of the fastening member to be used is provided, and the initial length of the fastening member to be used stored in the storage means is compared with the initial length of the fastening member measured before fastening. The fastening members having different initial lengths can be excluded.

According to the tightening force control device for a hydraulic torque wrench of the present invention, it is possible to measure the tightening force of a fastening member with a simple mechanism using an ultrasonic probe. It can also be applied to a torque wrench.
In this case, the fastening force of the fastening member can be measured in real time while the fastening member is fastened or immediately after the fastening member is fastened, and the fastening force of the fastening member is controlled (fastening of the fastening member). (Control of the end time of work) and quality control can be performed with high accuracy.

  Then, the initial length of the fastening member to be used stored in the storage means for storing the initial length of the fastening member to be used in advance is compared with the initial length of the fastening member measured before fastening, and the initial length differs. The fastening member can be eliminated.

1 shows an embodiment of a hydraulic torque wrench to which a tightening force control device for a hydraulic torque wrench of the present invention is applied, (A) is a front sectional view, (B) is a detailed front sectional view of a tip end portion of a main shaft, (C) And (D) is explanatory drawing of operation | movement of an adjustment mechanism, (E) And (F) is explanatory drawing which shows the attachment structure to the ultrasonic probe of a probe. The main axis | shaft of the same hydraulic torque wrench is shown, (A) is front sectional drawing, (B) is a top view, (C) is AA sectional drawing of (B). It is a front view which shows the different Example of the hydraulic torque wrench to which the control apparatus of the clamping force of the hydraulic torque wrench of this invention is applied. It is front sectional drawing which shows the hitting torque generator of the conventional hydraulic torque wrench. It is explanatory drawing which shows operation | movement of the hit | damage torque generator of the conventional hydraulic torque wrench. It is front sectional drawing which shows the hitting torque generator of the conventional hydraulic torque wrench. (A) is XX sectional drawing of FIG. 6, (B) is YY sectional drawing of FIG. A cam is shown, (A) is a front view, (B) is a side view. A check valve is shown, (A) is a front sectional view and (B) is a side view. It is explanatory drawing which shows operation | movement of the hit | damage torque generator of the conventional hydraulic torque wrench.

  Embodiments of a tightening force control device for a hydraulic torque wrench according to the present invention will be described below with reference to the drawings.

  1 to 2 show an embodiment of a hydraulic torque wrench to which a control device for tightening force of a hydraulic torque wrench according to the present invention is applied.

An example of this hydraulic torque wrench is shown. The impact torque generating device T of this hydraulic torque wrench W is a liner formed on a liner L, similar to the conventional impact torque generating device described in FIGS. The chamber La is filled with hydraulic oil, and the blade insertion groove Sa and the spring insertion hole Sb are provided in the main shaft S that is coaxially inserted into the liner L. The blade Bl is disposed in the blade insertion groove Sa, and the spring Sp is disposed in the spring insertion hole Sb. And the blades Bl are always urged by the springs Sp in the direction of the outer periphery of the main shaft to be brought into contact with the inner peripheral surface of the liner chamber La and sealed to the outer peripheral surface of the main shaft S and the inner peripheral surface of the liner chamber La. The surface is formed.
When the liner L is rotated by the air motor R, the seal surface formed on the inner peripheral surface of the liner chamber La matches the seal surface formed on the outer peripheral surface of the main shaft S and the blades Bl. A striking torque is generated.

  Further, the hydraulic torque wrench W includes an ultrasonic probe Se1, an angle sensor Se2, and a torque sensor Se3 as a measuring means for tightening the hydraulic torque wrench.

  The ultrasonic probe Se1 utilizes the property that a fastening member such as a bolt is tightened to cause elastic deformation, and the propagation time of the ultrasonic wave propagating through the fastening member changes according to the elongation. First, the probe Sc of the ultrasonic probe Se1 is brought into contact with the head surface of the fastening member, and the difference in propagation time until the ultrasonic wave transmitted toward the tip of the fastening member is received as an echo is measured. Thus, the tightening force (axial force) of the tightened fastening member is calculated, and the tightening force can be measured with high accuracy.

In this embodiment, the ultrasonic probe Se1 is connected to the tip end portion of the main shaft S via the adjusting mechanism Ss including the spherical bearing Ss1 and the spring Ss2 that urges the ultrasonic probe Se1 from the back side. Is arranged.
Thereby, the vibration of the ultrasonic probe Se1 and the fastening member when the probe Sc of the ultrasonic probe Se1 is brought into contact with the head surface of the fastening member, and the ultrasonic probe Se1 by the adjustment mechanism Ss. The measurement accuracy can be improved by improving the adhesion between the probe Sc of the ultrasonic probe Se1 and the fastening member.

In the present embodiment, a socket So is attached to the tip of the spindle S, and an adjustment mechanism Ss including a spring Ss2 that biases the spherical bearing Ss1 and the ultrasonic probe Se1 from the back side is attached to the socket So. The ultrasonic probe Se1 is detachably disposed.
As a result, the ultrasonic probe Se1 is shared among a plurality of types of sockets So corresponding to fastening members such as bolts, and when the socket So is consumed, the ultrasonic probe Se1 is changed from the worn socket So. Etc. can be removed and assembled into a new socket So.
In addition, at the socket So of the spindle S and the tip of the spindle S, an ultrasonic probe Se1 and a cable Ca1 led out into a wrench body W0 described later are respectively connected to the ultrasonic probe Se1 and the tip of the spindle S. Electrical connection is made via the provided connector Con.
As a result, the socket So can be easily attached and detached, and the workability at the time of replacement with the socket So corresponding to the fastening member can be improved.
A member such as an ultrasonic probe Se1 may be directly disposed on the main shaft S.

Further, in this embodiment, the probe Sc of the ultrasonic probe Se1 is made of synthetic resin or rubber, and preferably made of silicon rubber which has low attenuation of ultrasonic waves and excellent durability and chemical resistance. A probe made of a member is used.
In this case, although not particularly limited, as shown in FIGS. 1E and 1F, the probe Sc has a spherical bearing Ss1 by adopting a fitting structure such as a bottomed cylindrical cap shape. The ultrasonic probe Se1 can be detachably attached to the ultrasonic probe Se1 disposed by being fitted to the tip of the housing.
This improves the measurement accuracy by improving the adhesion between the probe Sc of the ultrasonic probe Se1 and the fastening member when the probe Sc of the ultrasonic probe Se1 is brought into contact with the head surface of the fastening member. In addition, the ultrasonic probe Se1 can be prevented from being damaged by the impact received from the head surface of the fastening member during the fastening operation of the fastening member, and only the probe Sc that is a consumable item can be prevented. Can be easily replaced.

Further, in order to measure and manage the fastening force (axial force) of the fastening member by transmitting an ultrasonic wave toward the tip of the fastening member by the ultrasonic probe Se1 and sending a signal received as an echo to the controller Co. In addition, the cable Ca1 is electrically connected to the ultrasonic probe Se1, and the cable Ca1 is inserted into the impact torque generating device T and the air motor R and led into the wrench body W0. A connection mechanism such as a rotary connector Rc disposed in the wrench main body W0 behind the motor R is connected.
The connecting mechanism such as the rotary connector Rc is connected to a fastening member measuring device (not shown) via a cable (not shown), etc., and measures and manages the fastening force of the fastening member. ing.
The cable Ca1 is connected to a rotary connector Rc or the like disposed in the wrench body W0 without being inserted through the air motor R when the rotation shaft of the air motor R is not directly connected to the main shaft S. To connect to.
Thus, the ultrasonic probe Se1 can be used to measure the tightening force of the fastening member, and the electrical connection mechanism is disposed in the wrench body W0 behind the air motor R. It can be configured simply.
In this case, the fastening force of the fastening member can be measured in real time while the fastening member is fastened or immediately after the fastening member is fastened, and the fastening force of the fastening member is controlled (fastening of the fastening member). (Control of the end time of work) and quality control can be performed with high accuracy.

  In the present embodiment, the controller Co is caused to propagate ultrasonic waves from the ultrasonic probe Se1 disposed at the distal end portion of the spindle S to the fastening member, and the propagation time of echoes from the distal end surface of the fastening member is measured. From the fastening member length measuring means for measuring the length of the fastening member, the fastening member length measured by the fastening member length measuring means, and the initial length of the fastening member measured before fastening, The fastening force measuring means for measuring the fastening force of the fastening member in real time during the fastening work, and the fastening work by stopping the motor R when the fastening force of the fastening member measured by the fastening force measuring means reaches a predetermined value. Motor control means for ending the process.

  This controller Co calculates the length of the fastening member when the fastening force of the fastening member reaches a predetermined value from the initial length of the fastening member measured before fastening, and the fastening member length measuring means By comparing with the measured length of the fastening member, it is determined that the fastening force of the fastening member has reached a predetermined value.

  Further, the controller Co includes storage means for storing in advance the initial length of the fastening member to be used, and the initial length of the fastening member to be used stored in the storage means and the initial length of the fastening member measured before fastening. And fastening members having different initial lengths are excluded. Specifically, in the case of fastening members having different initial lengths, warnings such as error display and buzzer are performed.

  In this embodiment, the cable Ca1 electrically connected to the ultrasonic probe Se1 is inserted into the impact torque generator T according to the structure of the impact torque generator T as shown in FIG. As shown in FIG. 4, the hole Sh through which the cable Ca1 is inserted is formed in the main shaft S so as to bypass the blade insertion groove Sa and the spring insertion hole Sb.

  In addition, the hole Sh through which the cable Ca1 formed in the striking torque generator is inserted is, for example, when the striking torque generator having no blade insertion groove and spring insertion hole shown in FIGS. 6 to 10 is used. As in the embodiment shown in FIG. 3, the main shaft S can be formed linearly.

  Further, in order to insert the cable Ca1 electrically connected to the ultrasonic probe Se1 through the inside of the air motor R, depending on the structure of the air motor R, the pipe P through which the cable Ca1 is inserted is connected to the air motor R. The rotary shaft is coaxially arranged so as to be rotatable.

As the angle sensor Se2, various rotation sensors such as a magnetic sensor and an optical sensor can be used. In this embodiment, a rotor iron core provided on the spindle S and a wrench so as to face the rotor iron core. Using a magnetic sensor composed of a stator core and a stator coil provided in the main body W0, a signal detected by the stator coil is processed by the substrate E, and an electric signal processed by the substrate E is transmitted via the cable Ca2 or the like. Thus, it is sent to the controller Co connected to the hydraulic torque wrench W, and the rotation angle of the main shaft S is measured and managed to detect the malfunction of the fastening member.
And the measurement of the fastening force of the fastening member by the ultrasonic probe Se1 and the measurement of the rotation angle of the spindle S can be performed in real time while performing the fastening operation of the fastening member. For example, the plastic region of the fastening member The tightening force control (control of the end time of the fastening operation of the fastening member) and quality control can be performed with high accuracy.

Various torque sensors such as a magnetostrictive sensor and a strain gauge sensor can be used as the torque sensor Se3. In this embodiment, the magnetostrictive portion provided on the main shaft S and the magnetostrictive portion are opposed to each other. Using a magnetostrictive sensor composed of an excitation detection coil provided in the wrench body W0, a signal detected by the excitation detection coil is processed by the substrate E, and an electrical signal processed by the substrate E is converted into a cable Ca2 or the like. Then, it is sent to a controller Co connected to a hydraulic torque wrench W, and the torque applied to the spindle S is measured and managed to detect a failure of the fastening member.
The measurement of the fastening force of the fastening member by the ultrasonic probe Se1 and the measurement of the torque applied to the spindle S can be performed in real time while performing the fastening operation of the fastening member. It is possible to control the tightening force in the plastic region (control of the end time of the fastening operation of the fastening member) and quality control with high accuracy.

  As described above, the control device for the tightening force of the hydraulic torque wrench according to the present invention has been described based on a plurality of embodiments. However, the present invention is not limited to the configuration described in the above embodiments, and the generation of impact torque. Other known systems (for example, a hitting torque generating device described in Patent Document 3) may be applied to the device, or an electric motor may be applied instead of an air motor as a drive source motor. The configuration can be changed as appropriate without departing from the spirit of the invention, such as application to a stationary hydraulic torque wrench having a plurality of main shafts.

  The tightening force control device for a hydraulic torque wrench according to the present invention can measure the tightening force of a fastening member with a simple mechanism using an ultrasonic probe, and can also fasten a bolt or the like. Since it is possible to eliminate erroneous assembly of members, it can be suitably used for hand-held hydraulic torque wrench applications that require high-precision management of the tightening force of fastening members, as well as other hydraulic torque wrench applications. Can also be used.

W Hydraulic Torque Wrench W0 Wrench Main Body T Impact Torque Generator L Liner La Liner Chamber S Spindle Sa Blade Insertion Slot Sb Spring Insertion Hole Sh Cable Insertion Hole Bl Blade Sp Spring So Socket R Air Motor (Motor)
Se1 Ultrasonic probe Se2 Angle sensor Se3 Torque sensor Sc Probe Ss Adjustment mechanism Ss1 Spherical bearing Ss2 Spring Ca1 Cable Ca2 Cable Rc Rotary connector P Pipe E Substrate Co controller Con connector A Oil chamber B Oil chamber C Cylinder 1 End of outer casing 11 Face wall 12 Cylinder part 13 Output adjustment mechanism 2 Inner casing 21 End face wall 22 Cylinder part 3 Main shaft 4 Cam 41a, 41b Cam groove 42a, 42b Oil guide hole 5 Check valve 6 Spring 71, 72, 73, 74 Seal member 81, 82 Pin 9 Fixing member

Claims (3)

In a control device for tightening force of a hydraulic torque wrench in which an ultrasonic probe is disposed at the tip of a main shaft that generates a striking torque via a striking torque generator that is rotationally driven by a motor ,
Fastening member that measures the length of the fastening member by propagating ultrasonic waves from the ultrasonic probe disposed at the tip of the main shaft to the fastening member and measuring the propagation time of the echo from the tip surface of the fastening member A length measuring means of
A fastening force measurement that measures the fastening force of the fastening member in real time during a fastening operation from the length of the fastening member measured by the fastening member length measuring means and the initial length of the fastening member measured before fastening. Means,
Motor control means for stopping the fastening operation by stopping the motor when the fastening force of the fastening member measured by the fastening force measuring means reaches a predetermined value;
A device for controlling a tightening force of a hydraulic torque wrench.   From the initial length of the fastening member measured before fastening, the fastening member length when the fastening force of the fastening member reaches a predetermined value is calculated, and the fastening member measured by the fastening member length measuring means 2. The tightening force control device for a hydraulic torque wrench according to claim 1, wherein it is determined that the fastening force of the fastening member has reached a predetermined value by comparing with a length of the hydraulic torque wrench.   Storage means for storing the initial length of the fastening member to be used in advance is provided, and the initial length of the fastening member to be used stored in the storage means is compared with the initial length of the fastening member measured before fastening. 3. A control device for tightening force of a hydraulic torque wrench according to claim 1, wherein fastening members having different lengths are excluded.

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