JP2000329056A - Hydraulic tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic tool which can reduce a motor torque even when load to be applied to a piston is increased, and also reduce power consumption. SOLUTION: This hydraulic tool has a work extruded and driven by a hydraulic pump driven which is driven by a motor 130. The hydraulic pump has a swash plate device 1 in which a swash plate 7 is supported to a support shaft 6 of a rotary shaft 5 and energized in a tilting state by a spring 8, and pistons 37 arranged on the swash plate 7 so as to be reciprocatingly inserted into a plurality of cylinder recessions 33 faced to the swash plate 7 and reciprocated according to the rotation of the swash plate 7 at their fronts. The cylinder recession 33 has a cylinder device 2 provided with a discharge part and a suction part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic tool such as a crimping tool provided with a hydraulic pump and used for crimping a crimp terminal to an electric wire.

[0002]

2. Description of the Related Art As a hydraulic pump to be mounted on a hydraulic tool such as a crimping tool, a cylinder device having a plurality of piston parts protrudingly biased, and the pistons are rotated by rotating the ends of the piston parts slidably in contact therewith. And a swash plate for reciprocating the section.

This fluid pressure pump discharges, for example, into a cylinder chamber of another cylinder device to drive an external drive piston thereof, and opens and closes the concave and convex types of the crimping die by the force of the external drive piston. A crimp terminal can be swaged to the end of the electric wire.

[0004]

However, in this fluid pressure pump, even if the load applied to the external drive piston from the crimping terminal or the like increases, the piston or the like is stroked with the same stroke amount, so that the rotational torque increases. However, there is a disadvantage that the power consumption of the motor increases.

Accordingly, an object of the present invention is to provide a hydraulic tool that can reduce the rotational torque of a motor and reduce power consumption even when a load applied to a piston portion increases.

[0006]

According to a first aspect of the present invention, there is provided a hydraulic tool including a motor, a hydraulic pump driven by the motor, and a work portion advanced by the hydraulic pump. The hydraulic pump has a rotating shaft connected to a motor shaft, has a supporting shaft having a different axial direction from the rotating shaft, and is provided around the supporting shaft so as to be inclined with respect to the axial direction of the rotating shaft. A swash plate device having a swash plate rotatably provided, and having a swash plate restoring means for restoring the swash plate to an inclined posture, and a cylinder disposed to face the swash plate, and the cylinder includes the swash plate. Forming a plurality of cylinder recesses that are substantially parallel to the rotation axis and open toward the swash plate,
The bottom of each of these cylinder recesses has a discharge portion that can be discharged from the cylinder recess via a check valve, and is inserted into each of the openings of the cylinder recess so as to be able to advance and retreat, and the tip ends in accordance with the rotation of the swash plate. A cylinder device having a piston portion disposed on the swash plate so as to reciprocate, and having suction means for sucking a fluid into the bottom of the cylinder recess by the advance operation of the piston portion. .

According to the hydraulic tool of the first aspect, when the load applied to the work portion increases and the load applied to the piston portion of the hydraulic pump increases, the swash plate is pushed against the inclination posture restoring means, and the swash plate is pushed. The tilt angle of the plate changes. When the inclination angle of the swash plate is reduced, the stroke of the piston portion is shortened, the discharge amount of the fluid is reduced, and the fluid is gradually pumped to the discharge portion. Since such a load is reduced, low power consumption with low torque can be realized.

According to a second aspect of the present invention, in the hydraulic tool according to the first aspect, the work portion is disposed on an output piston driven forward and backward of an output cylinder device connected to a discharge portion of the hydraulic pump. .

According to the hydraulic tool of the second aspect, the same effect as that of the first aspect is obtained.

According to a third aspect of the present invention, in the hydraulic tool according to the first aspect, the suction means is provided with a suction port on the front end side of the piston portion, a discharge port on the rear end side, and the suction port is connected to the discharge port. A check valve operable to perform a discharge operation is provided in a passage between the outlet and the outlet.

According to the third aspect of the present invention, in addition to the same effects as those of the first aspect, since the piston is provided on the piston without providing the suction means on the side surface of the cylinder, the cylinder can be made small and small. Can be.

According to a fourth aspect of the present invention, in the hydraulic tool according to the second aspect, the hydraulic pump is disposed in an oil chamber, the oil chamber is connected to an oil tank, and the output cylinder device is connected via a release valve and a pressure reducing valve. It is connected to the oil tank.

According to the hydraulic tool of the fourth aspect, in addition to the same effects as those of the first aspect, the fluid can be circulated, so that the hydraulic tool is effective as a portable hydraulic tool.

According to a fifth aspect of the present invention, in the hydraulic tool according to the first, second, third or fourth aspect, the swash plate has a thrust plate rotatably provided on a surface thereof through a thrust bearing. The piston is urged in the forward direction by a spring, and the tip of the piston is pressed against the thrust plate.

According to the hydraulic tool of the fifth aspect, in addition to the same effects as those of the first, second, third and fourth aspects, the tip of the piston portion is brought into direct contact with the swash plate to slide. As compared with the motor, the rotational resistance of the thrust plate can be reduced, and the rotational load of the motor can be reduced.

According to a sixth aspect of the present invention, in the hydraulic tool according to the first aspect, the work portion has a convex shape which is clamped to a concave shape in a pressure bonding die.

According to the hydraulic tool of the sixth aspect, in addition to the same effects as those of the first aspect, the hydraulic tool is effective as a crimping tool for caulking a crimp terminal to an electric wire.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. That is, this hydraulic tool is a crimping tool used for caulking a crimp terminal to an end of an electric wire, and has a crimping die 120 attached to the tip of a tool body housing (not shown) as shown in FIG. It is. A concave mold 21 is provided at the opening / closing portion 123 of the crimping die 120, and a convex mold 122 as a work portion is provided at the tip of the output piston 51 of the output cylinder device.
1 and the convex mold 122 are opened.

The crimping of the crimp terminal is performed as follows. That is, an electric wire (not shown) and a crimping terminal (not shown) are inserted between the concave die 121 and the convex die 122 of the crimping die by opening and closing the opening / closing part 123, and the convex die 12 of the crimping die is inserted.
2 moves closer to the concave mold 121 by the operation of the output piston 51, and the crimp terminal is crimped to the electric wire.

As shown in FIG. 1, a motor 130 and a motor 13 are provided inside a tool body housing (not shown).
A hydraulic pump driven at 0 and an output cylinder device 3 connected to the hydraulic pump are housed. The hydraulic pump and the output cylinder device 3 constitute a power device for a crimping tool. Power is supplied to the motor 130 from a power supply such as a battery pack (not shown) mounted on the tool body housing or a commercial AC power supply.

The hydraulic pump is an axial rotation type, has an axial fluid pressure pump having an automatic variable type swash plate, and has an automatic flow rate adjusting mechanism, and is provided with a swash plate device 1 and a cylinder device 2. The swash plate device 1 is attached to one end opening of a cylindrical oil chamber 4 that fills a fluid, for example, oil.
The cylinder device 2 is attached to a small-diameter opening at the other end of the cylindrical oil chamber 4, and the oil chamber 4 is filled with oil.

The swash plate device 1 has a rotating shaft 5 serving as a power transmission shaft driven by a motor 130, a supporting shaft 6 having a different axial direction from the rotating shaft 5, and a sliding surface 7a having a rotating surface 7a. 5
A swash plate 7 rotatably provided around the support shaft 6 so as to be inclined with respect to the axial direction of the swash plate. And a spring 8 that moves. Instead of providing the support shaft 6 on the rotating shaft 5, a notch 24a is formed in the flange 24 of the rotating shaft 5 as shown in FIG.
The projecting leg 7b provided at the end of the swash plate 7 may be rotatably supported by the support shaft 6 in a notch 24a located on the opposite side of the rotation shaft 5 with respect to the spring 8. In this case, one end of the swash plate 7 is pushed up by the spring 8, and the swash plate 7 is biased to be inclined about the support shaft 6 at the other end.
In other words, while the rotating shaft 5 and the supporting shaft 6 intersect in the same plane in FIG. The position of the support shaft 6 with respect to the swash plate 7 may be in the vicinity of the trajectory where the piston portion 37 rotates on the swash plate 7, but is preferably outside the trajectory.

In this embodiment, the base end 17 of the rotary shaft 5 is mounted at the center of the motor mount 9 via a bearing 15, and the distal end 5 a of the rotary shaft 5 is provided at the center of the cylinder device 2 via the bearing 16. It is attached to the recess.
The motor 130 is mounted on the motor mount 9 and the motor 1
The drive shaft 30 and the base end 17 of the rotary shaft 5 are connected. The motor mount 9 is in contact with an opening edge of one end of the oil chamber 4 and is fixed to a screw hole 18 provided in the opening edge together with a motor 130 by a bolt (not shown). The cylinder device 2 has a screw 19 formed on the outer periphery, is screwed and attached to a female screw formed on the inner peripheral surface at the other end of the oil chamber 4, and has an O-ring 20 in a circumferential groove formed on the peripheral surface of the cylinder device 2. Put on the oil chamber 4
Liquid-tightly adhered to the inner periphery of Further, the motor mount 9 has a projection 11 fitted into the opening of the oil chamber 4.
A peripheral groove is formed on the peripheral surface of the oil chamber 4, and an O-ring 21 is mounted on the peripheral groove, and the peripheral surface of the oil chamber 4 is liquid-tightly adhered. Reference numeral 22 denotes an oil seal provided on the projection 11.

The rotary shaft 5 is provided with a flange 24 at a position in the oil chamber 4, a long stopper 25 using a pin, for example, is provided on one side of the flange 24 with respect to the rotary shaft 5, and a pin is provided on the other side. The used short stopper 26 is provided upright.
The support shaft 6 is provided at right angles to the rotation shaft 5 in the oil chamber 4 by, for example, a fulcrum pin. The swash plate 7 is attached to both ends of the support shaft 6 with a through hole 7b at the center for inserting the rotary shaft 5, and is rotatable between a pair of stoppers 25 and 26. The rotation range is, for example, about 1.5 to 10 degrees with respect to a direction perpendicular to the rotation axis 5. The spring 8 uses, for example, a plurality of coil springs, and is compressed and interposed between the flange 24 and the swash plate 7 on the long stopper 25 side, inclining the swash plate 7 in a direction away from the flange 24, and as shown in FIG. It is locked to a short stopper 26. The spring 8 can be a leaf spring or a combination thereof in addition to a coil spring.

The cylinder device 2 has a cylinder 30 which is arranged to face the sliding surface 7a of the swash plate 7.
A plurality of cylinder recesses 33 are formed substantially parallel to the rotating shaft 5 and open toward the swash plate 7, and the bottom of these cylinder recesses 33 can be discharged from the cylinder recesses 33 via a first check valve 34. It has a discharge portion 35, and has a piston portion 37 which is inserted into each opening of the cylinder concave portion 33 so as to be able to advance and retreat, and is arranged on the swash plate 7 so that the tip moves forward and backward in accordance with the rotation of the swash plate 7. In addition, there is provided suction means for sucking fluid at the bottom of the cylinder recess 33 by the advance operation of the piston portion 37.

In the embodiment, the cylinder 30 of the cylinder device 2 is attached to the other end of the oil chamber 4. As shown in FIG. 7, five cylinder recesses 33 are arranged at equal intervals around the center in the circumferential direction, and a discharge portion 35 having a first check valve 34 is provided at the bottom through a communication passage 44 having a small diameter. Have been. The piston portion 37 has a distal end slidably in contact with the sliding surface 7a of the swash plate 7 and is pressed and urged by a spring 36. A spring receiving portion 46 using a ring is provided at the distal end.
7, one end of a spring 36 using a coil spring, for example, is engaged with the spring receiving portion 46, and the other end is engaged with the front end engaging concave portion of the cylinder concave portion 33 of the cylinder 30.
And the partial spherical surface at the tip of the piston portion 37 is in contact with the sliding surface 7 a of the swash plate 7. Thus, when the swash plate 7 rotates together with the rotation of the rotating shaft 5, the piston portion 37 repeats one reciprocating stroke with one rotation of the swash plate 7.

As shown in the enlarged view of FIG. 8, the suction means is provided with a suction port 39 at the tip end of the piston portion 37 and a discharge port 40 at the rear end of the piston portion 37. Check valve 4 operable to discharge into passage 41 between
2 are provided. The second check valve 42 includes a ball valve 42a, a spring 42b that presses the ball valve 42a, and a screw portion 42c that supports the spring 42b. The screw portion 42c is screwed into a female screw formed in the discharge port 40, and a valve such as a ball valve 42
a contacts the valve seat 41b at the end of the small-diameter portion 41a on the suction port 39 side of the passage 41. When the screwing amount of the screw portion 42c is adjusted, the force with which the ball valve 42a presses the valve seat 41b is adjusted. The suction port 39 is located in the oil chamber 4 at the time of the suction operation in which the cylinder recess 33 advances toward the swash plate 7 side.
Since the volume of the cylinder 3 increases, the cylinder recess 33 becomes negative pressure, the ball valve 42a of the second check valve 42 is opened from the valve seat 41b, and the oil in the oil chamber 4 is sucked into the cylinder recess 33 from the suction port 39. (FIG. 8 (b)). On the other hand, piston part 3
7, the volume of the cylinder recess 33 decreases during the retreat operation, and the oil in the cylinder recess 33 is pressurized. However, the second check valve 42 is opened because the ball valve 42a is pressed in the direction to close the valve seat 41b. And remains closed (FIG. 8 (a)).
Therefore, the pressurized oil is discharged to the discharge unit 35 as described later.

The output cylinder device 3 has a cylinder chamber 50 serving as a discharge chamber of the cylinder device 2 connected to the discharge portion 35, and the output piston 5 inserted into the cylinder chamber 50.
One. The output piston 51 includes a contact portion 55 that slides on the inner peripheral surface of the cylinder chamber 50 and a driving piece 56 provided at the center of the contact portion 55. An O-ring 57 is provided in a circumferential groove on the outer peripheral surface of the contact portion 55, and is in fluid-tight contact with the inner peripheral surface of the cylinder chamber 50. The output piston 51 is urged by a spring 90 in a direction to reduce the internal volume of the cylinder chamber 50. The spring 90 according to the embodiment is a coil spring, and the coil spring is passed through the driving piece 56, one end of which is engaged with the contact portion 55, and the other end thereof is attached to the cylinder chamber 50.
The output piston 51 is biased toward the cylinder device 2 by being locked to the zero side.

The end of the oil chamber 4 on the side of the cylinder device 2 is attached to the bottom wall 50a of the cylinder chamber 50. Discharge unit 3
Numeral 5 is configured to extend over the cylinder device 2 and the output cylinder device 3, and the end of the discharge section 35 communicates with the cylinder chamber 50. The first check valve 34 is composed of a spring supported at one end of the discharge portion 35 and a valve, for example, a ball valve supported at the tip of the spring and abutting against a valve seat at the boundary between the discharge portion 35 and the communication passage 44. . Accordingly, when the cylinder recess 33 of the cylinder device 2 is compressed by the piston portion 37, the pressure of the communication portion 44 increases, and the ball valve is pushed from the valve seat to open the valve, and the oil in the cylinder recess 33 passes through the discharge portion 35. The oil flows into the cylinder chamber 50, and the oil accumulates in the cylinder chamber 50. As described above, since the output piston 51 of the output cylinder device 3 is provided with the spring 90 in the direction of compressing the cylinder chamber 50,
Normally, the output piston 51 is retracted into the cylinder chamber 50. However, the output piston 51 is pressed by the oil pressure due to the reciprocating operation of the piston portion 37 of the cylinder device 2, and the output piston 51 advances outward against the spring 90. I do. On the other hand, the reverse flow of the oil is prevented because the ball valve of the first check valve 34 is pressed against the valve seat by the oil and comes into close contact therewith.

As described above, the swash plate 7, the piston 37
And the cylinder 30 are disposed in the oil chamber 4, the oil chamber 4 is connected to the oil tank 100, and the cylinder chamber 50
Is connected to the oil tank 100 via a release valve 70 and a pressure reducing valve 60.

As shown in FIG. 2, a pressure reducing valve 60 is provided in the bottom wall 50a of the cylinder chamber 50. This pressure reducing valve 6
Reference numeral 0 denotes a bottomed hole 61 opened on the side surface of the bottom wall 50a, a small-diameter communication passage 62 communicating with the inside of the cylinder chamber 50 at the bottom of the bottomed hole 61, and a communication passage 62 inserted into the bottomed hole 61. Of a third check valve having a conical portion for closing the outlet of the valve, a spring 64 for pressing the valve body 63 toward a valve seat, and a bottomed hole 61
And a pressure adjusting portion 65 that supports a spring by providing a screw that engages with a female screw formed on the opening side of the spring. The spring pressure of the spring 64 is changed according to the screwing amount of the pressure adjusting section 65 to adjust the pressure for pressing the valve body 63 against the valve seat, so that the pressure becomes equal to the oil pressure in the communication passage 62 communicating with the cylinder chamber 50. The position, that is, the pressure at which the valve body 63 is pushed by the oil pressure to open and decompress the cylinder chamber 50 is adjusted. The pressure adjusting section 65 is provided with an O-ring 66 in an outer circumferential groove to prevent oil leakage. 67 is an outlet formed on the side of the bottomed hole 61.

As shown in FIG. 3, a release valve 70 is provided on the bottom wall 50a of the cylinder chamber 50. Release valve 70
A valve chamber 72 of a fourth check valve communicating with the cylinder chamber 50 through a communication section 71, and an end of the valve chamber 72 and a small-diameter communication passage 7;
The valve chamber 72 is provided with a valve for closing a communication passage 73 communicating with the operation chamber 74, for example, a ball valve 75.
Is pressed by a spring 76. The operation chamber 74 is opened on the outer surface of the bottom wall 50a, the end of the operation piece 77 protrudes from this opening, and is urged to protrude to the outside by a spring 78.
A push piece 79 capable of pressing the ball valve 75 through the communication passage 73 is provided at the inner end of the nozzle 7. Reference numeral 80 denotes an oil outlet formed on the side of the operation chamber 74. Output piston 5 of cylinder device 3
In the case of retreating 1, the operating piece 77 is pushed and the pressing piece 79 is pushed.
By pushing the ball valve 75 open against the spring 76, the oil in the cylinder chamber 50 flows out of the cylinder chamber from the oil outlet 80 through the communication passage 73 and the operation chamber 74 by the pressure.

As shown in FIG. 1 again, an oil tank 100 adjacent to the oil chamber 4 is provided on the bottom wall 50a of the cylinder chamber 50.
And a communication path 101 that connects the oil tank 100 and the four oil chambers is formed in the bottom wall 50a, and a filter 103 is mounted at an outlet on the oil tank 100 side.
The outlet 67 of the bottomed hole 61 of the pressure reducing valve 60 and the oil outlet 80 of the operation chamber 74 of the release valve 70 are connected to the oil tank 100.
Contact Oil tank 100 is formed of a flexible member.

The operation of the crimp terminal crimping device will be described. FIGS. 1 and 4 show the operation at the time of pressurization for terminal crimping. The output piston 51 of the output cylinder device 3 is retracted by a spring 90, and the cylinder chamber 50 is in a minimum space. The oil pressure in the chamber 50 is also at a minimum. At this time, the swash plate 7 is pressed against the short stopper 26 by the spring 8 of the swash plate 7. When the motor 130 rotates, the rotating shaft 5 and the swash plate 7 rotate, and the piston portion 37 slides on the sliding surface 7a,
The piston part 37 reciprocates in the axial direction. In this reciprocating operation, when the piston portion 37 advances from the cylinder concave portion 33 toward the swash plate 71 by the spring 36, the internal volume of the cylinder concave portion 33 increases, so that oil is sucked into the cylinder concave portion 33 from the suction port 39, When the piston portion 37 is retracted into the cylinder recess 33 by the swash plate 7, the internal volume in the cylinder recess 33 is compressed. At the time of this compression, the second check valve 42 does not flow backward to the suction port 39 side in the piston portion 37, but pushes the first check valve 34 of the discharge portion 35 open to pump oil into the cylinder chamber 50. I do. The piston portion 37 makes one reciprocation with one rotation of the swash plate 7, but since the inclination angle of the swash plate 7 is the maximum at this time, the reciprocation stroke of the piston portion 37 is also maximum, and therefore, the oil pressure per one reciprocation is sent. The amount is also maximum. In the cylinder chamber 50 in the output cylinder device 3 in which the oil is pumped from the piston portion 37, the internal pressure of the cylinder chamber 50 is sequentially increased by the oil, and the output piston 51 advances. For this reason, the crimping dies 12
The 0 convex mold 122 moves closer to the concave mold 121.

FIGS. 2 and 5 show the operation from pressurizing operation for terminal caulking to pressure reducing valve operation for keeping the maximum pressure from the completion of caulking to a constant value. A load is applied to 51, and the oil is pressurized by the load to press the first check valve 34 of the discharge unit 35. For this reason, a load is applied to the discharge operation of the piston portion 37 that generates the hydraulic pressure that pushes the first check valve 34 open.
A load is applied to the spring 8 of the swash plate 7 that pushes the piston portion 37, and the spring 8 is elastically deformed. As a result, when the oil pressure exceeds the spring force of the spring 8 in the cylinder chamber 50, the spring 8 is compressed and deformed accordingly, and the inclination angle of the swash plate 7 approaches the direction perpendicular to the rotary shaft 5, and the spring 8 It will have a tilt angle with balanced pressure. Further, since the piston load is applied at the time of discharge, the piston portion 37 is pushed when the swash plate 7 is rotated and is applied to the swash plate 7 so that the spring 8 is incorporated at that position, which is efficient. When the angle of the swash plate 7 with respect to the piston 37 is reduced, the reciprocating stroke of the piston 37 is reduced, and the load on the motor 130 is also reduced. When the maximum load is applied, the swash plate 7 is engaged with the long stopper 25, but also at this time, the swash plate 7 has an inclination (for example, about 1.5 °) for reciprocating the piston portion 37. In this case, the pressure in the cylinder chamber 50 is kept constant by the operation of the pressure reducing valve 60. The operation of the pressure reducing valve 60 is adjusted by the pressure adjusting unit 65, and is set to the maximum pressure for caulking the crimp terminal. Therefore, although the crimping terminal is securely caulked, the pressure reducing valve 60 is opened for a certain pressure of oil or more, so that no excessive caulking force is applied to the crimping terminal. The swash plate 7 may be inclined so that the piston portion 37 does not reciprocate when the load is the maximum.

FIGS. 3 and 6 show the release operation. When the operation button 77 is pressed, the release valve 70 is pressed and opened, and the oil in the cylinder chamber 50 flows out of the cylinder chamber 50 to reduce the pressure. . Due to the decrease in the pressure, the spring 90 of the output piston 51 returns and pushes the output piston 51 back, so that the oil is pushed out and the spring 8 of the swash plate 7 is no longer loaded, so that the swash plate 7 returns to the maximum angle. The inclined stopper 26 is engaged with the short stopper 26.

When the motor 130 is kept operating,
Since the output piston 51 reciprocates in this step, it is possible to continuously crimp the crimp terminal. However, the motor 130 may be stopped every time the output piston 51 retreats.

The circulation of the oil will be described. The oil is filled in the oil chamber 4 and the oil tank 100, and communicates with each other through the communication passage 101 and the filter 103. The oil tank 100 is, for example, a flexible tank having a capacity of about 55 cc as described above. Oil chamber 4
When the oil is sucked into the cylinder concave portion 33 by the discharge operation of the piston portion 37, the oil flows into the oil chamber 4 sequentially from the oil tank 100 through the filter 103 and the communication passage 101, and the oil tank 100 is flexible. Therefore, they contract as shown in FIGS. The oil sucked into the cylinder recess 33 is sequentially sent to the cylinder chamber 50 in the output cylinder device 3 under pressure, and the volume of the cylinder chamber 50 is expanded by the movement of the piston 51. Cylinder chamber 50
When the oil is depressurized, the pressure reducing valve 60 is opened and the oil is returned to the oil tank 100, and when released, the release valve 70 is opened and returned to the oil tank 100. Thus, the oil circulates.

According to the first embodiment, when the hydraulic pressure of the output cylinder device 3 is low and the force for pushing up the piston is less than the compression load of the spring 8, the inclination angle of the swash plate 7 is large and the discharge amount is large. Since the shaft rotation torque (load) at this time is small, a large discharge amount can be obtained with a smaller power to the hydraulic pump. When the hydraulic pressure is high and the piston pushing-up force compresses the spring 8, the inclination angle of the swash plate 7 changes according to the piston pushing-up force. At this time, the shaft rotation load is usually very large. However, since the inclination angle of the swash plate 7 is reduced due to the bending of the spring 8, a discharge amount corresponding to a small piston lifting force is obtained with a small shaft rotation torque. As a result, low fuel consumption and low power can be realized as compared with the conventional example in which the inclination angle is fixed.

FIGS. 9 and 10 show a second embodiment of the present invention. That is, the hydraulic pump used for this hydraulic tool is different from the hydraulic pump according to the first embodiment in that the piston 37
Swash plate 7 has a thrust plate 126 rotatably provided on a surface thereof via a thrust bearing 125, and the piston portion 3
7 is pressed against the thrust plate 126. Specifically, a circular recess 128 is formed on the surface of the swash plate 7, a ring-shaped groove 127 is formed at the bottom thereof, and the thrust bearing 125 includes a plurality of thrust roller bearings inserted into the ring-shaped groove 127. The thrust plate 126 is fitted in the circular recess 128 and is supported by the thrust bearing 125. 130 is a motor.

FIG. 9 (similarly in FIG. 4) shows a case in which the swash plate 7 has a maximum inclination angle of 10 °. Assuming that the diameter is 3791 cm and the diameter of the cylinder recess 33 is 0.4 cm, and the number of the cylinder recesses 33 is 5, the discharge amount is (0.4 / 2) ² ×
3.14 × 0.3791 × 5 = 0.238 CC / 1 cycle.

FIG. 10 (similarly in FIG. 5) shows a case where the swash plate 7 has a minimum inclination angle of 1.5 °.
Assuming that the lift amount L2 for pushing up the oil into the cylinder chamber 50 is, for example, 0.0564 cm, the discharge amount is (0.4
/ 2) ² × 3.14 × 0.0564 × 5 = 0.035C
C / 1 cycle. The other parts are the same as those of the first embodiment, and the common parts are denoted by the same reference numerals.

According to the second embodiment, the piston 3
As compared with a structure in which the tip of the thrust plate 7 abuts on the swash plate 7 and slides directly, the rotational resistance of the thrust plate 126 can be reduced, and the rotational load of the motor 130 can be reduced.

FIG. 11 is a graph in which the horizontal axis represents time (seconds) and the vertical axis represents motor current (A). A ₁ is the maximum angle 10 ° hydraulic pump by fixing the swash plate to the inclination of the graph ,, A ₂ is the minimum angle 1.5 ° in the case of operating the hydraulic pump by fixing the swash plate to the inclination angle of graph when the driving, a ₃ is a graph of the embodiment swash plate 7 is automatically changed range of the angle 1.5 ° to 10 °. The swash plate 7 is rotated and oil is output from the cylinder device 2 to the output cylinder device 3.
The total discharge amount of oil when the oil is discharged, that is, the maximum pressure applied to the output piston 51 is set to the same constant value in each case, and the time required to reach the maximum pressure is determined by the final positions a _{1 to} a _{3 in} each graph. It has become. At this time, the area under each graph, that is, the current × time (AS), is 203 AS in graph A ₁ , 199 AS in graph A ₂ , and graph A
₃ was 136 AS. From this result, graph A ₁ ,
A ₂ is no change much even different angle of the swash plate 7, graph A ₃ it can be seen that smaller about 67% of the graphs A _1. When the current (A) × time (S) is multiplied by the applied voltage (V) of the motor, the amount of electric power is obtained. Therefore, since each value is proportional to the amount of electric power, the present invention reduces power consumption as compared with the conventional example. We can see that we can do it.

In the present invention, the fluid may be other than oil.

A rotary shaft 5 for supporting the support shaft 6 of the swash plate 7
A long hole may be formed in at least one of the swash plate 7 and the support shaft 6 may be moved according to a change in the inclination angle of the swash plate 7.

In the embodiment, the crimping tool has been described as an example, but other than this, a hydraulic tool such as a wire or bolt cutting device may be used.

Further, although the suction means is provided on the piston portion 37, it may be provided with a check valve on the side of the cylinder recess 33, in which case the swash plate 7 does not have to be immersed in oil.

Further, the piston portion 37 of the first embodiment
May have a ball joint provided with a shoe. The tip of the piston portion 37 of the second embodiment may be connected to the thrust plate 126 by a ball joint or the like, and the spring for urging and pushing the piston portion 37 may be omitted.

Further, as the means for restoring the inclined posture of the swash plate 7, there are a spring 8 and a magnet utilizing magnetic force. Further, the spring 36 may be compressed and interposed between the end surface of the piston portion 37 and the bottom surface of the cylinder recess 33 in the cylinder recess 33.

The spring 42b of the second check valve 42 is shown in FIG.
The ball valve 4 is supported by the screw portion 42c as shown in FIG.
Compression may be interposed between 2a and the bottom surface of the cylinder recess 33.

[0052]

According to the hydraulic tool of the first aspect, when the load applied to the work portion increases and the load applied to the piston portion of the hydraulic pump increases, the swash plate is pushed against the inclination posture restoring means. , The inclination angle of the swash plate changes. When the inclination angle of the swash plate is reduced, the stroke of the piston portion is shortened, the discharge amount of the fluid is reduced, and the fluid is gradually pumped to the discharge portion. Since such a load is reduced, low power consumption with low torque can be realized.

According to the hydraulic tool of the second aspect, the same effect as that of the first aspect is obtained.

According to the third aspect of the present invention, in addition to the same effects as those of the first aspect, since the piston is provided on the piston without providing the suction means on the side surface of the cylinder, the cylinder can be made small and small. Can be.

According to the hydraulic tool of the fourth aspect, in addition to the same effects as those of the first aspect, the fluid can be circulated, so that the hydraulic tool is effective as a portable hydraulic tool.

According to the hydraulic tool of the fifth aspect, in addition to the same effects as those of the first, second, third, or fourth aspect, the tip of the piston portion is directly contacted with the swash plate to slide. As compared with the motor, the rotational resistance of the thrust plate can be reduced, and the rotational load of the motor can be reduced.

According to the hydraulic tool of the sixth aspect, in addition to the same effect as the first aspect, the hydraulic tool is effective as a crimping tool for caulking a crimp terminal to an electric wire.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing an operation state during pressurization according to a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a state during a pressurizing operation and a state during a pressure reducing valve operation.

FIG. 3 is a partial cross-sectional view of a state during a release operation.

FIG. 4 is an enlarged partial cross-sectional view of a main part explaining the operation of a swash plate.

FIG. 5 is an enlarged partial cross-sectional view of a main part during the pressurizing operation and the pressure reducing valve operation.

FIG. 6 is an enlarged partial cross-sectional view of a main part in a state during a release operation.

FIG. 7 is an explanatory view of the cylinder device as viewed in the axial direction.

FIG. 8 is an enlarged sectional view showing a check valve of a piston portion;
(A) is a state where the check valve is closed, and (b) is a state where the check valve is open.

FIG. 9 is a partial cross-sectional view of the second embodiment at the time of initial pressurization.

FIG. 10 is a partial sectional view at the time of maximum pressurization.

FIG. 11 is a graph of motor current versus time for the present invention and the prior art.

FIG. 12 is a partial cross-sectional view of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Swash plate device 2 Cylinder device 3 Output cylinder device 4 Oil chamber 5 Rotation shaft 6 Support shaft 7 Swash plate 8 Spring 25 Stopper 26 Stopper 30 Cylinder 33 Cylinder recess 34 First check valve 35 Discharge part 36 Spring 37 Piston part 39 Suction port 40 Discharge port 42 Second check valve 50 Cylinder chamber 51 Output piston 60 Pressure reducing valve 70 Release valve 90 Spring 100 Oil tank 120 Crimping die 125 Thrust bearing 126 Thrust plate 130 Motor

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshihiro Sakamoto 1048 Kazuma Kadoma, Osaka Pref. Matsushita Electric Works, Ltd. Inside (72) Inventor Yuichi Higuchi 3-1-1, Fukuichicho, Higashiosaka-shi, Osaka Co., Ltd. Takako (72) Inventor Yoshitaka Minami 3-1-1, Fukuichi-cho, Higashi-Osaka City, Osaka Co., Ltd. (72) Inventor Yoshiko Ishizaki 3-1-1, Fukuichi-cho, Higashi-Osaka City, Osaka Stock Company F-term in Takako company (reference) 3C039 FA04 3H070 AA01 BB04 BB17 BB25 CC21 DD52 DD66 5E063 CA01 CB20 CC10 CD02 XA20

Claims (6)

[Claims] 1. A hydraulic tool comprising a motor, a hydraulic pump driven by the motor, and a work part driven and advanced by the hydraulic pump, wherein the hydraulic pump has a rotating shaft connected to a motor shaft. Having a supporting shaft having a different axial direction from the rotating shaft, and having a swash plate rotatably provided around the supporting shaft so as to be inclined with respect to the axial direction of the rotating shaft, A swash plate device having an inclined posture restoring means for restoring the swash plate to an inclined posture, and a cylinder disposed opposite to the swash plate, and an opening in the cylinder substantially parallel to the rotation axis toward the swash plate. A plurality of cylinder recesses are formed, and at the bottom of these cylinder recesses, a discharge portion capable of discharging from the cylinder recesses via a check valve is inserted. Is the rotation of the swash plate A cylinder device having a piston portion disposed on the swash plate so as to perform reciprocating operation in accordance with the above, and having suction means for sucking fluid at the bottom of the cylinder recess by the advance operation of the piston portion. Hydraulic tools. 2. The hydraulic tool according to claim 1, wherein the work portion is provided on an output piston driven forward and backward of an output cylinder device connected to a discharge portion of the hydraulic pump. 3. The reverse suction means is provided with a suction port on the front end side of the piston portion, a discharge port on a rear end side, and capable of performing a discharge operation in a passage between the suction port and the discharge port. The hydraulic tool according to claim 1, further comprising a stop valve. 4. The oil pump is disposed in an oil chamber, the oil chamber is connected to an oil tank, and the output cylinder device is connected to the oil tank via a release valve and a pressure reducing valve. Hydraulic tools. 5. The swash plate has on its surface a thrust plate rotatably provided via a thrust bearing,
5. The hydraulic tool according to claim 1, wherein the piston is urged in a forward direction by a spring, and a tip of the piston is pressed against the thrust plate. 6. 6. The hydraulic tool according to claim 1, wherein the work portion has a convex shape which is clamped to a concave shape in a crimping die.