JP7215788B1 - cylinder type actuator - Google Patents

Abstract

A cylinder-type actuator capable of generating a large driving force at an arbitrary timing during high-speed movement of a drive shaft is provided. A cylinder-type actuator in one embodiment includes a drive shaft, a first cylinder section for controlling axial advancement or retraction of the drive shaft, and a first cylinder drive section for operating the first cylinder section. a second cylinder portion for controlling the axial advancement or retraction of the drive shaft and the first cylinder portion using a working fluid; and a second cylinder drive portion for operating the second cylinder portion; Prepare. [Selection drawing] Fig. 1

Description

The present invention relates to cylinder type actuators. More particularly, it relates to cylinder-type actuators that include a cylinder and a drive shaft.

2. Description of the Related Art Conventionally, in a molding machine such as a die casting machine, when using a die having a core, a cylinder type actuator is used to insert or withdraw the core from the die. A cylinder-type actuator is a device that moves a rod (also called a drive shaft) fixed to a piston in the axial direction by driving a piston arranged in a cylinder tube with electrical or hydraulic energy. The core can be inserted or withdrawn by connecting the core to the tip of the rod and operating the cylinder type actuator to move the rod.

When the core is pulled out of the mold, the molding machine needs to pull the core away from the product, so a large driving force is required for the cylinder type actuator. Further, after the core is separated from the product, it is required to operate the cylinder type actuator at high speed to retract the core at high speed in order to shorten the cycle time of the molding machine. In order to meet such demands, Patent Documents 1 to 3 disclose cylinder type actuators having a function of electrically moving a rod using a ball screw and a function of hydraulically moving a piston to retract the rod. disclosed.

JP 2021-087977 A Japanese Patent No. 6952387 Japanese Patent Application Laid-Open No. 2001-295805

The conventional cylinder-type actuator described above can generate a large driving force using hydraulic energy at the initial movement when the rod is pulled away from the product, but after that, the ball screw can only be used to retract the rod. In other words, the conventional cylinder type actuator has a problem that it cannot cope with the case where a large driving force is required except for the initial movement when the rod is pulled away from the product.

One of the objects of the present invention is to provide a cylinder-type actuator capable of generating a large driving force at an arbitrary timing during high-speed movement of the drive shaft.

A cylinder-type actuator according to one embodiment of the present invention includes a drive shaft, a first cylinder section for controlling axial advancement or retreat of the drive shaft, and a first cylinder drive section for operating the first cylinder section. a second cylinder section for controlling the axial advance or retreat of the drive shaft and the first cylinder section using a working fluid; and a second cylinder drive section for operating the second cylinder section. Prepare.

In the above cylinder-type actuator, the second cylinder part may include a second cylinder and a piston rod fixed to the front end of the first cylinder part. The piston rod may have a cylindrical portion passing through the second cylinder, and an annular piston portion disposed along the outer circumference of the cylindrical portion and positioned inside the second cylinder. good. The drive shaft may pass through the inner side of the tubular portion. The inside of the second cylinder may be divided into two second cylinder chambers by the cylindrical portion and the piston portion. The second cylinder driving section may control the advancing or retreating of the piston rod in the axial direction by generating a pressure difference in the working fluid between the two second cylinder chambers.

In the cylinder-type actuator described above, the first cylinder drive section may operate the first cylinder section with rotational power.

In the cylinder-type actuator, the first cylinder part includes a first cylinder, a threaded shaft penetrating through the rear end of the first cylinder and inserted into the first cylinder, and A nut may be included secured to the rearward end of the drive shaft and threaded onto the threaded shaft. A front end of the screw shaft may be inserted into a hollow portion provided in the drive shaft. The first cylinder portion may move the nut and the drive shaft forward or backward in the axial direction by rotating the screw shaft.

In the above cylinder type actuator, the first cylinder drive section may operate the first cylinder section by a pressure difference of working fluid.

The cylinder-type actuator may further include a control section that controls the first cylinder driving section and the second cylinder driving section. The first cylinder section may include a first cylinder and a piston fixed to the rear end of the drive shaft and dividing the interior of the first cylinder into two first cylinder chambers. The first cylinder drive unit includes a motor, a pressure pump driven by the motor and discharging the working fluid, a motor amplifier provided between the control unit and the motor, and the operation in the pipe. A directional control valve may be included to control the direction of fluid movement. The first cylinder drive section may advance or retreat the piston and the drive shaft in the axial direction by generating a pressure difference in the working fluid between the two first cylinder chambers. The control section may control the second cylinder driving section based on a current value output from the motor amplifier.

The cylinder-type actuator may further include a control section that controls the first cylinder driving section and the second cylinder driving section. The first cylinder section may include a first cylinder and a piston fixed to the rear end of the drive shaft and dividing the interior of the first cylinder into two first cylinder chambers. The first cylinder drive section may include a directional control valve that controls a moving direction of the working fluid in the pipe, and a pressure sensor that detects internal pressures of the two first cylinder chambers. The first cylinder drive section may advance or retreat the piston and the drive shaft in the axial direction by generating a pressure difference in the working fluid between the two first cylinder chambers. The control section may control the second cylinder driving section based on a detection value output from the pressure sensor.

1 is a schematic diagram showing the configuration of a cylinder-type actuator according to a first embodiment; FIG. It is the figure which looked at the 2nd cylinder part in the cylinder type actuator of 1st Embodiment from the back side. FIG. 4 is a flow chart for explaining the operation of the cylinder type actuator of the first embodiment; FIG. 5 is a schematic diagram showing the configuration of a cylinder-type actuator according to a second embodiment; FIG. 9 is a flow chart for explaining the operation of the cylinder type actuator of the second embodiment; FIG. 10 is a schematic diagram showing the configuration of a cylinder-type actuator according to a third embodiment; FIG. 10 is a flow chart for explaining the operation of the cylinder type actuator of the third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention can be implemented in various aspects without departing from the gist thereof, and should not be construed as being limited to the description of the embodiments illustrated below. For example, specific structures shown in the drawings are merely examples and do not limit the present invention. In this specification and each drawing, elements having the same functions as those described with respect to the previous drawings may be denoted by the same reference numerals, and overlapping descriptions may be omitted.

In this specification and drawings, the direction in which the drive shaft protrudes from the first cylinder portion is called "forward", and the forward movement of the drive shaft is defined as "advance". Further, the direction in which the drive shaft advances into the first cylinder portion is called "rear", and the movement of the drive shaft rearward is defined as "retreat".

<First embodiment>
(Configuration of cylinder type actuator)
FIG. 1 is a schematic diagram showing the configuration of a cylinder-type actuator 100 according to the first embodiment. The cylinder-type actuator 100 of the present embodiment is a hybrid-type cylinder-type actuator that uses both rotational power drive and hydraulic drive.

The cylinder-type actuator 100 of this embodiment includes a drive shaft 110 , a first cylinder portion 120 , a second cylinder portion 130 , a first cylinder drive portion 140 , a second cylinder drive portion 150 and a control portion 160 . However, the configuration of the cylinder type actuator 100 of this embodiment is not limited to this example, and other elements may be added.

The drive shaft 110 is a rod-shaped member for moving a work (a driven body such as a mold or core). The drive shaft 110 of this embodiment is a cylindrical member made of a metal material and has a hollow portion 110a inside. As shown in FIG. 1 , the drive shaft 110 protrudes forward from inside the first cylinder 121 , passes through the second cylinder 131 , and protrudes forward beyond the second cylinder portion 130 . A workpiece is connected to the front end of the drive shaft 110 . In the following description, the longitudinal direction of the drive shaft 110 is called "axial direction".

The first cylinder portion 120 has a function of controlling the axial advance or retreat of the drive shaft 110 . The first cylinder part 120 of this embodiment includes a first cylinder 121 , a screw shaft 122 and a nut 123 . However, the first cylinder portion 120 is not limited to this example, and may include other elements.

The first cylinder 121 corresponds to the housing of the first cylinder portion 120 . The first cylinder 121 is a cylindrical member having a hollow portion inside, and front and rear ends thereof are closed by lids 121a and 121b, respectively. The lid portion 121a is provided with an opening portion 121aa through which the drive shaft 110 passes. The lid portion 121b is provided with an opening portion 121ba through which the screw shaft 122 passes.

The screw shaft 122 is a rod-shaped member having a common axis 10 with the drive shaft 110, and has a threaded outer peripheral surface. In this embodiment, a ball screw is used as the screw shaft 122 . The screw shaft 122 is inserted into the first cylinder 121 through the rear end of the first cylinder 121 . Specifically, the screw shaft 122 is inserted into the first cylinder 121 through an opening 121ba provided at the rear end of the first cylinder 121 . At this time, the front end of the screw shaft 122 is inserted into the hollow portion 110 a provided inside the drive shaft 110 . On the other hand, the rear end of the screw shaft 122 is connected to a driven side pulley 141b of a first cylinder driving portion 140, which will be described later.

The nut 123 is arranged inside the first cylinder 121 , is screwed onto the screw shaft 122 and is fixed to the rear end of the drive shaft 110 . Although illustration is omitted, the nut 123 is provided with a detent mechanism that engages with the inner wall of the first cylinder 121 so that the nut 123 does not rotate even when the screw shaft 122 rotates. . Therefore, as the screw shaft 122 rotates, the nut 123 and the drive shaft 110 advance or retreat in the axial direction inside the first cylinder 121 . However, since the outer diameter of the nut 123 is larger than the diameter of the openings 121aa and 121ba provided in the first cylinder 121, the movement of the nut 123 is restricted to the inside of the first cylinder 121.

As described above, the first cylinder portion 120 is a drive mechanism that converts the rotational motion of the screw shaft 122 into the linear motion of the drive shaft 110 . The first cylinder driving portion 140 that applies rotational power to the first cylinder portion 120 will be described later.

Next, the second cylinder portion 130 will be described. The second cylinder portion 130 has a function of controlling axial advancement or retraction of the drive shaft 110 and the first cylinder portion 120 using working fluid. The second cylinder part 130 of this embodiment includes a second cylinder 131 and a piston rod 132 . However, the second cylinder portion 130 is not limited to this example, and may include other elements. Further, in this embodiment, hydraulic oil is used as the working fluid, but the working fluid is not limited to this example. For example, other pressurizable working fluids such as water, air or gas can be used as the working fluid.

The second cylinder 131 corresponds to the housing of the second cylinder portion 130 . The second cylinder 131 is a cylindrical member having a hollow portion inside, and front and rear ends thereof are closed by lids 131a and 131b, respectively. The lids 131a and 131b are provided with openings 131aa and 131ba through which the piston rod 132 (specifically, the tubular portion 132a of the piston rod 132) penetrates.

Although illustration is omitted, when using the cylinder-type actuator 100, the second cylinder 131 is fixed by screwing or the like to a fixed base fixed to a mold or the like. That is, the second cylinder 131 is fixed with respect to a work object such as a mold.

The piston rod 132 is a member used in combination with the second cylinder 131, and includes a tubular portion 132a and a piston portion 132b. The tubular portion 132 a is a cylindrical portion of the piston rod 132 and passes through openings 131 aa and 131 ba provided in the second cylinder 131 . Further, the drive shaft 110 passes through the inside of the tubular portion 132a. As shown in FIG. 1 , the rear end of the tubular portion 132 a is fixed to the front end of the first cylinder 121 of the first cylinder portion 120 . Here, an example in which the cylindrical portion 132a and the first cylinder 121 are configured as separate members will be described, but both may be integrated.

The piston portion 132b is a portion of the piston rod 132 that protrudes in a direction substantially perpendicular to the longitudinal direction of the cylindrical portion 132a (horizontal direction in FIG. 1). As shown in FIG. 1, the piston portion 132b is located inside the second cylinder 131. As shown in FIG. At this time, since the outer diameter of the piston portion 132b is larger than the diameters of the openings 131aa and 131ba of the second cylinder 131, the movement of the piston portion 132b is restricted to the inside of the second cylinder 131.

FIG. 2 is a rear view of the second cylinder portion 130 of the cylinder-type actuator 100 of the first embodiment. Specifically, FIG. 2A is a view of the second cylinder 131 viewed from the rear side, and FIG. 2B is a view of the piston rod 132 viewed from the rear side. As shown in FIG. 2B, the piston portion 132b of this embodiment is an annular member arranged along the outer circumference of the tubular portion 132a. Although FIG. 2B shows an annular member as the piston portion 132b, the shape of the piston portion 132b is not limited to this example, and the external shape of the piston portion 132b may be polygonal.

Further, as shown in FIGS. 1 and 2A, a gap 15 is formed between the opening 131ba of the second cylinder 131 and the tubular portion 132a, and the inner wall of the second cylinder 131 and the piston portion 132b are separated. A gap 16 is formed between them. At this time, the gaps 15 and 16 are each sealed with the sealing material 20 . In the second cylinder portion 130, the sealing materials 20 are all indicated by black circles.

In this way, the inside of the second cylinder 131 is divided into the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b by the cylindrical portion 132a and the piston portion 132b. As described above, the second cylinder 131 is a cylindrical member, and the piston portion 132b is also an annular member. It becomes a space with a shape.

The second cylinder portion 130 of this embodiment is controlled using a working fluid (in this embodiment, hydraulic oil). Specifically, hydraulic fluid discharged from a second cylinder driving portion 150, which will be described later, is supplied to the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b. As a result, a pressure difference in hydraulic fluid is generated between the two second cylinder chambers, and the generated pressure difference advances or retreats the piston rod 132 . At this time, since the piston rod 132 is fixed to the first cylinder 121 of the first cylinder portion 120, the drive shaft 110 and the first cylinder portion 120 move forward or backward in the axial direction as the piston rod 132 moves.

As described above, the second cylinder portion 130 is a drive mechanism that converts the power generated by the pressure difference of the hydraulic oil into linear motion of the drive shaft 110 and the first cylinder portion 120 . A second cylinder driving portion 150 that supplies hydraulic oil to the second cylinder portion 130 will be described later.

Next, the first cylinder driving section 140 will be described. The first cylinder driving portion 140 has a function of operating the first cylinder portion 120 with rotational power. Specifically, the first cylinder drive section 140 is a drive section that generates and transmits rotational power to be applied to the screw shaft 122 of the first cylinder section 120 .

As shown in FIG. 1 , the first cylinder drive section 140 includes a power transmission section 141 , a braking section 142 , a first motor 143 and a first motor amplifier 144 . The power transmission unit 141 is a winding transmission device having a drive pulley 141a, a driven pulley 141b, and a drive belt 141c. Rotational power generated by the first motor 143 is transmitted to the drive-side pulley 141a. The rotational power transmitted to the driving side pulley 141a is transmitted to the driven side pulley 141b via the driving belt 141c. A screw shaft 122 is connected to the driven pulley 141b, and rotational power is transmitted to the screw shaft 122 by rotation of the driven pulley 141b.

The output of the first motor 143 is controlled by the first motor amplifier 144 . Specifically, based on the instruction signal from the control unit 160, the first motor amplifier 144 controls the first motor 143 to rotate to the required position at the required speed and torque. The output of the first motor 143 is returned to the first motor amplifier 144 for feedback control.

The braking portion 142 has a role of stopping the driven pulley 141 b and stopping the rotation of the screw shaft 122 . Specifically, in this embodiment, an electromagnetic brake is used as the braking section 142 . The electromagnetic brake (braking portion 142) shown in FIG. 1 includes an electromagnetic coil 142a, a spring 142b and a brake disk 142c, but other elements may be added. The braking portion 142 of this embodiment is adapted to transmit the movement of the piston rod 132 to the drive shaft 110 when the drive shaft 110 and the first cylinder portion 120 are moved forward or backward by the second cylinder portion 130. stop the rotation.

Next, the second cylinder driving section 150 will be described. The second cylinder driving portion 150 has a function of operating the second cylinder portion 130 by a pressure difference of working fluid (here, working oil). Specifically, the second cylinder driving section 150 supplies hydraulic oil to the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b of the second cylinder section 130, A hydraulic oil pressure difference is generated between them. Thereby, the second cylinder driving portion 150 controls the axial advance or retreat of the piston rod 132 .

As shown in FIG. 1 , the second cylinder driving section 150 includes a pressurizing pump 151 , a second motor 152 and a second motor amplifier 153 . The pressure pump 151 is a pump that discharges hydraulic oil, and in this embodiment, a hydraulic pump is used. The pressurizing pump 151 is operated by power supplied from the second motor 152, and supplies hydraulic oil to the front side second cylinder chamber 31a or the rear side second cylinder chamber 31b depending on the moving direction of the drive shaft 110. controlled to

Specifically, when advancing the piston rod 132 (that is, when advancing the drive shaft 110), the pressure pump 151 supplies hydraulic oil to the rear second cylinder chamber 31b (path indicated by B). Conversely, when the piston rod 132 is retracted (that is, when the drive shaft 110 is retracted), the pressure pump 151 supplies hydraulic oil to the front second cylinder chamber 31a (path indicated by A).

The output of the second motor 152 is controlled by a second motor amplifier 153 . Specifically, based on the instruction signal from the control unit 160, the second motor amplifier 153 operates until the front-side second cylinder chamber 31a or the rear-side second cylinder chamber 31b holds the required hydraulic pressure (that is, , until a necessary pressure difference is generated between the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b). The output of the second motor 152 is returned to the second motor amplifier 153 for feedback control.

As described above, in the present embodiment, both the first cylinder drive section 140 and the second cylinder drive section 150 can be used to move the drive shaft 110 forward or backward. Whether the drive shaft 110 is moved using the first cylinder drive unit 140 or the second cylinder drive unit 150 is output from the first motor amplifier 144 and the second motor amplifier 153. The control unit 160 determines based on the current value. The operation of the cylinder type actuator 100 of this embodiment will be described below.

(Operation of cylinder type actuator)
FIG. 3 is a flow chart for explaining the operation of the cylinder type actuator 100 of the first embodiment. Specifically, FIG. 3 shows an example of the operation of the cylinder type actuator 100 when a temporary overload occurs while the work connected to the front end of the drive shaft 110 is being moved at high speed. there is

As shown in FIG. 3 , when the cylinder type actuator 100 operates, the first cylinder driving section 140 drives the first cylinder section 120 . That is, the control unit 160 moves the drive shaft 110 by operating the power transmission unit 141 using the first motor 143 (step S301).

In step S<b>301 , first, the first motor amplifier 144 operates the first motor 143 according to an instruction from the control section 160 . Rotational power of the first motor 143 is transmitted to the screw shaft 122 via the power transmission portion 141, and the screw shaft 122 rotates. Rotation of the screw shaft 122 advances the nut 123 and the drive shaft 110 in the axial direction. Since the control by the first cylinder driving section 140 is an electrical control, high-speed operation is possible and high accuracy can be obtained. Therefore, the first cylinder portion 120 can advance the drive shaft 110 at high speed and with high accuracy. For example, the drive shaft 110 can be moved at a speed of about 200 mm/sec under the control of the first cylinder portion 120 .

Next, the control unit 160 monitors the current value output from the first motor amplifier 144 and determines whether or not the current value exceeds the rated maximum torque of the first motor 143 (step S302). When an event that prevents forward movement of the drive shaft 110 occurs, a high driving force (torque) is required (overload is applied) to the first motor 143, so the current value output from the first motor amplifier 144 increases. . The control unit 160 detects this change in current value and determines whether or not the torque required for the first motor 143 has exceeded the rated maximum torque of the first motor 143 .

When determined as NO in step S302, the control unit 160 determines whether or not the work is finished (step S351). If the determination in step S351 is YES, the control unit 160 terminates the control of the first cylinder drive unit 140. FIG. If NO is determined in step S351, the control unit 160 returns to step S302 and monitors the output of the first motor amplifier 144 again.

When determined as YES in step S302, the first cylinder driving section 140 stops the first motor 143 and operates the braking section 142 (step S303). In step S303, the electromagnetic brake functioning as the braking portion 142 is activated, and the rotation of the screw shaft 122 is stopped by the brake disk 142c. If the rotation of the screw shaft 122 can be stopped by operating the first motor 143 at the rated maximum torque, the braking portion 142 can be omitted.

After operating the braking portion 142 , the second cylinder driving portion 150 drives the second cylinder portion 130 . That is, the control unit 160 moves the drive shaft 110 by operating the pressure pump 151 using the second motor 152 (step S304).

In step S<b>304 , first, the second motor amplifier 153 operates the second motor 152 according to an instruction from the control section 160 . The rotational power of the second motor 152 operates the pressurizing pump 151 to supply working oil to the rear second cylinder chamber 31b. As a result, the internal pressure of the hydraulic fluid in the rear second cylinder chamber 31b becomes higher than the internal pressure of the hydraulic fluid in the front second cylinder chamber 31a, and the piston rod 132 moves forward. At this time, since the first cylinder 121 and the screw shaft 122 are fixed by the braking portion 142, the movement of the piston rod 132 is transmitted to the drive shaft 110 as it is. That is, the drive shaft 110 advances in the axial direction in conjunction with the movement of the piston rod 132 .

The control by the second cylinder driving section 150 is hydraulic control and is configured to obtain a high driving force. For example, in this embodiment, a hydraulic pump capable of discharging hydraulic oil at high pressure is used as the pressurizing pump 151 . Therefore, the second cylinder portion 130 advances the drive shaft 110 with a high driving force, and can normally drive the drive shaft 110 without stopping halfway even if an event that hinders the movement of the drive shaft 110 occurs. . For example, according to the control by the second cylinder drive section 150, the drive shaft 110 moves at a relatively slow speed of about 20 mm/sec, but exhibits a higher driving force than the control by the first cylinder drive section 140. can be done.

Next, the control unit 160 monitors the current value output from the second motor amplifier 153 and determines whether or not the torque of the second motor 152 has fallen below a predetermined threshold (step S305). Specifically, control unit 160 determines whether the torque of second motor 152 has decreased to a value sufficient to move drive shaft 110 by first cylinder unit 120 . For example, the predetermined threshold can be set to 90% (preferably 80%) of the value corresponding to the rated maximum torque of the first motor 143 .

When determined as NO in step S305, the control unit 160 determines whether or not the work is completed (step S352). If determined as YES in step S352, the control unit 160 terminates the control of the second cylinder driving unit 150. FIG. If NO is determined in step S352, the control unit 160 returns to step S305 and monitors the output of the second motor amplifier 153 again.

If determined as YES in step S305, the second cylinder driving section 150 stops the second motor 152 (step S306). When the second motor 152 stops in step S306, the pressurizing pump 151 also stops, so the internal pressure of the hydraulic fluid is maintained in the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b, and the position of the piston rod 132 is Fixed.

After the second motor 152 is stopped, the first cylinder driving section 140 drives the first cylinder section 120 again. That is, the control unit 160 moves the drive shaft 110 by operating the power transmission unit 141 using the first motor 143 (step S307). As a result, the drive shaft 110 starts to move forward at high speed again.

Next, the control unit 160 determines whether or not the work has ended (step S308). If the determination in step S308 is YES, the control unit 160 terminates the control of the first cylinder drive unit 140. FIG. If NO is determined in step S308, the control unit 160 returns to step S302 and monitors the output of the first motor amplifier 144 again.

As described above, the cylinder-type actuator 100 of the present embodiment appropriately switches between control by the first cylinder driving section 140 capable of high-speed operation and control by the second cylinder driving section 150 capable of outputting a large driving force. , the drive shaft 110 can be moved at high speed or with a high driving force. In particular, the cylinder-type actuator 100 can switch from control by the first cylinder driving section 140 to control by the second cylinder driving section 150 regardless of the position of the drive shaft 110. It is possible to switch to a movement with a high driving force at any timing during high-speed movement, not just at the initial movement.

In this embodiment, regarding the operation of the cylinder type actuator 100, the case of moving the drive shaft 110 forward has been described, but it is also possible to move the drive shaft 110 backward by performing the same control. That is, when the drive shaft 110 is to be retracted, the first cylinder driving section 140 may rotate the first motor 143 in the opposite direction to the forward control. Further, the second cylinder driving portion 150 may supply hydraulic oil to the front side second cylinder chamber 31a.

Further, when the first cylinder driving portion 140 is operated, the pressurizing pump 151 is controlled to supply hydraulic oil to the front side second cylinder chamber 31a or the rear side second cylinder chamber 31b, thereby controlling the position of the piston rod 132. can be brought close to the intermediate position in the axial direction of the second cylinder 131 . If the piston rod 132 is brought closer to the intermediate position of the second cylinder 131, the moving distance (stroke) of the piston rod 132 can be increased when the control by the second cylinder drive unit 150 is executed again. The travel distance of the shaft 110 can be increased.

While the drive shaft 110 is being controlled by the first cylinder drive section 140, the drive shaft 110 is moving at high speed. Therefore, even if the piston rod 132 is moved by the second cylinder driving portion 150 while the drive shaft 110 is moving at a high speed, the movement of the drive shaft 110 is relatively small, so that the work is not substantially affected. I have nothing to give.

<Second embodiment>
(Configuration of cylinder type actuator)
A cylinder type actuator 200 according to a second embodiment of the present invention will be described with reference to FIG. In addition, in the cylinder type actuator 200 of the present embodiment, parts common to the cylinder type actuator 100 of the first embodiment are denoted by the same reference numerals, and description thereof may be omitted.

FIG. 4 is a schematic diagram showing the configuration of a cylinder-type actuator 200 according to the second embodiment. The cylinder-type actuator 200 of this embodiment includes a drive shaft 210 , a first cylinder portion 220 , a second cylinder portion 130 , a first cylinder drive portion 240 , a second cylinder drive portion 150 and a control portion 260 . However, the configuration of the cylinder type actuator 200 of this embodiment is not limited to this example, and other elements may be added.

The drive shaft 210 is a rod-shaped member for moving the work. The drive shaft 210 of this embodiment is a cylindrical member made of a metal material. As in the first embodiment, the drive shaft 210 protrudes forward from inside the first cylinder 221 , passes through the second cylinder 131 , and protrudes forward beyond the second cylinder portion 130 .

The first cylinder portion 220 has a function of controlling the axial advance or retreat of the drive shaft 210 . The first cylinder part 220 of this embodiment includes a first cylinder 221 and a piston 222 . However, the first cylinder part 220 is not limited to this example, and may include other elements.

The first cylinder 221 corresponds to the housing of the first cylinder portion 220 . The first cylinder 221 is a cylindrical member having a hollow portion inside, and front and rear ends thereof are closed by lids 221a and 221b, respectively. The lid portion 221a is provided with an opening portion 221aa through which the drive shaft 210 passes.

The piston 222 is arranged inside the first cylinder 221 and fixed to the rear end of the drive shaft 210 . Although FIG. 1 shows an example in which the drive shaft 210 and the piston 222 are separate members, the drive shaft 210 and the piston 222 may be integrated. At this time, the movement of the piston 222 is limited to the inside of the first cylinder 221 because the outer diameter of the piston 222 is larger than the diameter of the opening 221aa provided in the first cylinder 221 .

A seal material 30 is provided in the gap between the inner wall of the first cylinder 221 and the piston 222 . In the first cylinder portion 220, the sealing materials 30 are all indicated by black circles. Thus, the inside of the first cylinder 221 is divided by the piston 222 into the front first cylinder chamber 21a and the rear first cylinder chamber 21b. As described above, the first cylinder 221 is a cylindrical member, and the piston 222 is also a cylindrical member. becomes a space of

The first cylinder portion 220 of this embodiment is controlled using a working fluid (in this embodiment, hydraulic oil). The first cylinder driving portion 240 has a function of operating the first cylinder portion 220 by the pressure difference of the working oil. Specifically, the first cylinder driving section 240 supplies hydraulic oil to the front side first cylinder chamber 21a and the rear side first cylinder chamber 21b of the first cylinder section 220, A hydraulic oil pressure difference is generated between them. Thereby, the first cylinder driving section 240 controls the axial advancement or retraction of the piston 222 and the drive shaft 210 .

As shown in FIG. 1, the first cylinder driving section 240 includes a pressure pump 241, a first motor 242, a first motor amplifier 243, and directional control valves 244 and 245. As shown in FIG. The pressure pump 241 is a pump that discharges hydraulic oil, and in this embodiment, a hydraulic pump is used. The pressure pump 241 is operated by power supplied from the first motor 242, and supplies hydraulic oil to the front first cylinder chamber 21a or the rear first cylinder chamber 21b depending on the moving direction of the drive shaft 210. controlled to

Specifically, when advancing the piston 222 (that is, when advancing the drive shaft 210), the pressure pump 241 supplies hydraulic fluid to the first rear cylinder chamber 21b. Conversely, when the piston 222 is retracted (that is, when the drive shaft 210 is retracted), the pressure pump 241 supplies hydraulic fluid to the front first cylinder chamber 21a. When supplying hydraulic oil, both direction control valves 244 and 245 are opened.

The output of the first motor 242 is controlled by the first motor amplifier 243 . Specifically, based on an instruction signal from the control unit 260, the first motor amplifier 243 operates until the front side first cylinder chamber 21a or the rear side first cylinder chamber 21b holds the required hydraulic pressure (that is, , until a necessary pressure difference is generated between the front first cylinder chamber 21a and the rear first cylinder chamber 21b). The output of the first motor 242 is returned to the first motor amplifier 243 for feedback control.

The directional control valves 244 and 245 have the role of controlling the direction of movement of hydraulic fluid within the piping. In this embodiment, solenoid valves are used as the direction control valves 244 and 245 . However, it is not limited to this example, and it is also possible to use other valves having similar functions.

In the cylinder type actuator 200 of this embodiment, the second cylinder portion 130 and the second cylinder driving portion 150 have the same configurations as those of the cylinder type actuator 100 of the first embodiment, so detailed description thereof will be omitted. Also in the present embodiment, the second cylinder portion 130 converts the power due to the pressure difference of the hydraulic oil into linear motion of the drive shaft 210 and the first cylinder portion 220 . As in the first embodiment, the second cylinder portion 130 is controlled using hydraulic fluid. Specifically, a pressure difference is generated between the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b by the hydraulic fluid discharged from the second cylinder driving portion 150, and the generated pressure difference The piston rod 132 and drive shaft 210 are axially advanced or retracted.

As described above, in this embodiment, both the first cylinder drive section 240 and the second cylinder drive section 150 can be used to advance or retreat the drive shaft 210 . Whether the drive shaft 210 is moved using the first cylinder drive unit 240 or the second cylinder drive unit 150 is output from the first motor amplifier 243 and the second motor amplifier 153. The controller 260 determines based on the current value. The operation of the cylinder type actuator 200 of this embodiment will be described below.

(Operation of cylinder type actuator)
FIG. 5 is a flow chart for explaining the operation of the cylinder type actuator 200 of the second embodiment. Specifically, FIG. 5 shows an example of the operation of the cylinder type actuator 200 when a temporary overload occurs while the workpiece connected to the front end of the drive shaft 210 is being moved at high speed. there is

As shown in FIG. 5 , when the cylinder type actuator 200 operates, the first cylinder driving section 240 drives the first cylinder section 220 . That is, the control unit 260 moves the drive shaft 210 by operating the pressure pump 241 using the first motor 242 (step S401).

In step S<b>401 , first, the first motor amplifier 243 operates the first motor 242 according to an instruction from the control section 260 . The rotational power of the first motor 242 operates the pressurizing pump 241 to supply working oil to the rear first cylinder chamber 21b. As a result, the internal pressure of the hydraulic fluid in the rear first cylinder chamber 21b becomes higher than the internal pressure of the hydraulic fluid in the front first cylinder chamber 21a, and the piston 222 and the drive shaft 210 move forward.

In this embodiment, the control by the first cylinder driving section 240 is hydraulic control, and is configured to move the piston 222 at high speed. For example, in the present embodiment, a hydraulic pump with a large discharge amount per unit time is used as the pressurizing pump 241, so the drive shaft 210 can be moved forward at high speed.

Next, the control unit 160 monitors the current value output from the first motor amplifier 243 and determines whether or not the current value exceeds the rated maximum torque of the first motor 242 (step S402). When an event that prevents forward movement of the drive shaft 210 occurs, a high driving force (torque) is required (overload is applied) to the first motor 242, so the current value output from the first motor amplifier 243 increases. . The control unit 260 detects this change in current value and determines whether or not the torque required of the first motor 242 has exceeded the rated maximum torque of the first motor 242 .

When determined as NO in step S402, the control unit 260 determines whether or not the work is finished (step S451). If YES is determined in step S451, the control unit 260 terminates the control of the first cylinder driving unit 240. FIG. If NO is determined in step S451, the control unit 260 returns to step S402 and monitors the output of the first motor amplifier 243 again.

If the determination in step S402 is YES, the first cylinder driving section 240 stops the first motor 242 and closes the direction control valves 244 and 245 (step S403). In step S403, the solenoid valves functioning as the directional control valves 244 and 245 are actuated to be closed, and the internal pressure of the hydraulic oil in the front first cylinder chamber 21a and the rear first cylinder chamber 21b is maintained. Note that if it is possible to maintain the internal pressures of the front side first cylinder chamber 21a and the rear side first cylinder chamber 21b by operating the first motor 242 at the rated maximum torque, the direction control valves 244 and 245 may be operated. It can be omitted.

After actuating the directional control valves 244 and 245 , the second cylinder drive section 150 drives the second cylinder section 130 . That is, the control unit 260 moves the drive shaft 210 by operating the pressure pump 151 using the second motor 152 (step S404).

In step S<b>404 , first, the second motor amplifier 153 operates the second motor 152 according to an instruction from the control section 260 . The rotational power of the second motor 152 operates the pressurizing pump 151 to supply working oil to the rear second cylinder chamber 31b. As a result, the internal pressure of the hydraulic fluid in the rear second cylinder chamber 31b becomes higher than the internal pressure of the hydraulic fluid in the front second cylinder chamber 31a, and the piston rod 132 moves forward. At this time, in the first cylinder portion 220, since the internal pressure is maintained by the hydraulic fluid in the front first cylinder chamber 21a and the rear first cylinder chamber 21b, the position of the piston 222 inside the first cylinder 221 is fixed. be done. That is, since the first cylinder 221 and the drive shaft 210 are fixed, the movement of the piston rod 132 is transmitted to the drive shaft 210 as it is. Accordingly, the drive shaft 210 advances in the axial direction in conjunction with the movement of the piston rod 132 .

As described in the first embodiment, the control by the second cylinder driving section 150 is configured so as to obtain a high driving force. Therefore, the second cylinder portion 130 advances the drive shaft 210 with a high driving force, and can normally drive the drive shaft 210 without stopping halfway even if an event that hinders the movement of the drive shaft 210 occurs. .

Next, the control unit 260 monitors the current value output from the second motor amplifier 153 and determines whether or not the torque of the second motor 152 has fallen below a predetermined threshold (step S405). Specifically, control unit 260 determines whether the torque of second motor 152 has decreased to a value sufficient to move drive shaft 210 by first cylinder unit 220 . For example, the predetermined threshold can be set to 90% (preferably 80%) of the value corresponding to the rated maximum torque of the first motor 242 .

When determined as NO in step S405, the control unit 260 determines whether or not the work is finished (step S452). If the determination in step S452 is YES, the control unit 260 terminates the control of the second cylinder drive unit 150. FIG. If determined as NO in step S452, the control unit 260 returns to step S405 and monitors the output of the second motor amplifier 153 again.

When it is determined YES in step S405, the second cylinder driving section 150 stops the second motor 152 (step S406). When the second motor 152 stops in step S406, the pressurizing pump 151 also stops, so the internal pressure of the hydraulic fluid is maintained in the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b, and the position of the piston rod 132 is Fixed.

After the second motor 152 is stopped, the first cylinder driving section 240 drives the first cylinder section 220 again. That is, the control unit 260 moves the drive shaft 210 by operating the pressure pump 241 using the first motor 242 (step S407). As a result, the drive shaft 210 starts to move forward at high speed again.

Next, the control unit 260 determines whether or not the work has ended (step S408). If the determination in step S408 is YES, the control unit 260 terminates the control of the first cylinder drive unit 240. If NO is determined in step S408, the control unit 260 returns to step S402 and monitors the output of the first motor amplifier 243 again.

As described above, the cylinder-type actuator 200 of the present embodiment appropriately switches between control by the first cylinder driving section 240 capable of high-speed operation and control by the second cylinder driving section 150 capable of outputting a large driving force. , the drive shaft 210 can be moved at high speed or with a high driving force. In this embodiment, as in the first embodiment, the cylinder-type actuator 200 changes from the control by the first cylinder driving section 240 to the control by the second cylinder driving section 150 regardless of the position of the drive shaft 210. It is possible to switch. Therefore, it is possible to switch to a movement having a high driving force not only at the initial movement of the drive shaft 210 but also at any timing during high-speed movement.

In this embodiment, regarding the operation of the cylinder type actuator 200, the case of moving the drive shaft 210 forward has been described, but it is also possible to move the drive shaft 210 backward by performing the same control. That is, when the drive shaft 210 is retracted, the first cylinder driving section 240 may supply hydraulic oil to the front side first cylinder chamber 21a, and the second cylinder driving section 150 may supply hydraulic oil to the front side second cylinder chamber 31a. Hydraulic oil should be supplied.

<Third Embodiment>
(Configuration of cylinder type actuator)
A cylinder type actuator 300 according to a third embodiment of the present invention will be described with reference to FIG. In the cylinder-type actuator 300 of the present embodiment, portions common to the cylinder-type actuator 100 of the first embodiment and the cylinder-type actuator 200 of the second embodiment are denoted by the same reference numerals, and explanation thereof is omitted. There is

FIG. 6 is a schematic diagram showing the configuration of a cylinder type actuator 300 according to the third embodiment. The cylinder-type actuator 300 of this embodiment includes a drive shaft 210 , a first cylinder portion 320 , a second cylinder portion 330 , a first cylinder drive portion 340 , a second cylinder drive portion 350 and a control portion 360 . However, the configuration of the cylinder type actuator 300 of this embodiment is not limited to this example, and other elements may be added.

In the cylinder type actuator 300 of the present embodiment, the first cylinder portion 320 has a configuration in which a front side first pressure sensor 51a and a rear side first pressure sensor 51b are added to the first cylinder portion 220 of the second embodiment. It's becoming Therefore, the description of the basic structure of the first cylinder portion 320 is omitted, and the description will focus on the first front pressure sensor 51a and the first rear pressure sensor 51b.

The front first pressure sensor 51a is a sensor for detecting the internal pressure of the hydraulic fluid in the front first cylinder chamber 21a. The first rear pressure sensor 51b is a sensor for detecting the internal pressure of the hydraulic fluid in the first rear cylinder chamber 21b. The controller 360 monitors the detected values of the first front pressure sensor 51a and the first rear pressure sensor 51b. The control unit 360 compares the detection value of the first front pressure sensor 51a or the first rear pressure sensor 51b with a predetermined threshold value, and controls the first cylinder driving unit 340 based on the comparison result.

The second cylinder portion 330 has a configuration in which a second front pressure sensor 52a and a second rear pressure sensor 52b are added to the second cylinder portion 130 of the first embodiment. Therefore, the description of the basic structure of the second cylinder portion 330 is omitted, and the description will focus on the front side second pressure sensor 52a and the rear side second pressure sensor 52b.

The front second pressure sensor 52a is a sensor for detecting the internal pressure of the hydraulic fluid in the front second cylinder chamber 31a. The rear second pressure sensor 52b is a sensor for detecting the internal pressure of the hydraulic oil in the rear second cylinder chamber 31b. The controller 360 monitors the detected values of the front second pressure sensor 52a and the rear second pressure sensor 52b. The control unit 360 compares the detection value of the second front pressure sensor 52a or the second rear pressure sensor 52b with a predetermined threshold value, and controls the second cylinder driving unit 350 based on the comparison result.

In the cylinder-type actuator 300 of the present embodiment, similarly to the cylinder-type actuator 200 of the second embodiment, the first cylinder driving section 340 and the second cylinder driving section 350 are driven by the pressure difference between the hydraulic fluids. The second cylinder part 330 is activated. The first cylinder driving section 340 is still configured to operate at high speed, and the second cylinder driving section 350 is configured to output a large driving force.

The first cylinder drive section 340 includes a first directional control valve 341 and a first control valve amplifier 342 . The first directional control valve 341 is connected to a hydraulic unit (not shown). The first directional control valve 341 has a function of controlling the moving direction of hydraulic oil in the pipe, and is controlled by a first control valve amplifier 342 .

The first control valve amplifier 342 controls the first direction control valve 341 based on the instruction signal from the control unit 360 to determine the moving direction of the hydraulic oil flowing through the piping. The first cylinder drive section 340 supplies hydraulic oil to the front side first cylinder chamber 21a and the rear side first cylinder chamber 21b in the first cylinder section 320 by controlling the first direction control valve 341, A pressure difference is generated between the two first cylinder chambers to control forward or backward movement of the drive shaft 210 .

The second cylinder driving section 350 includes a second directional control valve 351 and a second control valve amplifier 352 . Since the functions of the second direction control valve 351 and the second control valve amplifier 352 are the same as the functions of the first direction control valve 341 and the first control valve amplifier 342, respectively, detailed description thereof will be omitted. The second cylinder driving portion 350 supplies hydraulic oil to the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b in the second cylinder portion 330 by controlling the second direction control valve 351, A pressure difference is generated between the two second cylinder chambers to control forward or backward movement of the drive shaft 210 .

As described above, in this embodiment, both the first cylinder drive section 340 and the second cylinder drive section 350 can be used to advance or retreat the drive shaft 210 . Whether the drive shaft 210 is moved using the first cylinder drive unit 340 or the second cylinder drive unit 350 is determined by the first front pressure sensor 51a and the first rear pressure sensor 51b. , the control unit 360 determines based on the detection values output from the front side second pressure sensor 52a and the rear side second pressure sensor 52b. The operation of the cylinder type actuator 300 of this embodiment will be described below.

(Operation of cylinder type actuator)
FIG. 7 is a flow chart for explaining the operation of the cylinder type actuator 300 of the third embodiment. Specifically, FIG. 7 shows an example of the operation of the cylinder type actuator 300 when a temporary overload occurs while the work connected to the front end of the drive shaft 210 is being moved at high speed. there is

As shown in FIG. 7 , when the cylinder type actuator 300 is actuated, the first cylinder portion 320 is driven by the first cylinder drive portion 340 . That is, the control unit 360 moves the drive shaft 210 by operating the first direction control valve 341 via the first control valve amplifier 342 (step S501).

In step S<b>501 , first, according to an instruction from the control unit 360 , the first control valve amplifier 342 operates the first direction control valve 341 to supply hydraulic fluid to the rear first cylinder chamber 21 b of the first cylinder unit 320 . As a result, the internal pressure of the hydraulic fluid in the rear first cylinder chamber 21b becomes higher than the internal pressure of the hydraulic fluid in the front first cylinder chamber 21a, and the piston 222 and the drive shaft 210 move forward.

In this embodiment, the control by the first cylinder driving section 340 is hydraulic control, and is configured to move the piston 222 at high speed. For example, in the present embodiment, the first directional control valve 341 is controlled so that the discharge amount per unit time is increased, so the drive shaft 210 can be advanced at high speed.

Next, the control unit 360 monitors the detection value from the rear first pressure sensor 51b and determines whether the detection value of the rear first pressure sensor 51b exceeds a predetermined threshold (step S502). . When an event that hinders the forward movement of the drive shaft 210 occurs, while the forward movement of the piston 222 is delayed, hydraulic oil continues to be supplied to the rear first cylinder chamber 21b, so the internal pressure of the rear first cylinder chamber 21b increases. That is, the detected value of the first rear pressure sensor 51b increases. Based on this change in the detected value, control unit 360 detects that an event that prevents forward movement of drive shaft 210 has occurred. As the predetermined threshold, for example, the supply pressure of the first direction control valve 341 (the upper limit of the pressure that can be supplied) may be set, or 90% (preferably 80%) of the value corresponding to the supply pressure. can be set to the value of

When determined as NO in step S502, the control unit 360 determines whether or not the work is finished (step S551). If YES is determined in step S551, the control unit 360 terminates the control of the first cylinder driving unit 340. FIG. If NO is determined in step S551, the control unit 360 returns to step S502 and monitors the detection value of the first rear pressure sensor 51b again.

If the determination in step S502 is YES, the first cylinder driving section 340 closes the first direction control valve 341 (step S503). In step S503, the first directional control valve 341 is closed to maintain the internal pressures of the front first cylinder chamber 21a and the rear first cylinder chamber 21b.

After closing the first directional control valve 341 , the second cylinder drive section 350 drives the second cylinder section 330 . That is, the second cylinder drive section 350 moves the drive shaft 210 by operating the second direction control valve 351 via the second control valve amplifier 352 (step S504).

In step S504, first, according to an instruction from the control unit 360, the second control valve amplifier 352 operates the second direction control valve 351 to supply hydraulic fluid to the rear second cylinder chamber 31b of the second cylinder unit 330. As a result, the internal pressure of the hydraulic fluid in the rear second cylinder chamber 31b becomes higher than the internal pressure of the hydraulic fluid in the front second cylinder chamber 31a, and the piston rod 132 moves forward. At this time, in the first cylinder portion 320, the internal pressure of the hydraulic oil in the front first cylinder chamber 21a and the rear first cylinder chamber 21b is maintained, so the position of the piston 222 inside the first cylinder 221 is fixed. be done. That is, since the first cylinder 221 and the drive shaft 210 are fixed, the movement of the piston rod 132 is transmitted to the drive shaft 210 as it is. Accordingly, the drive shaft 210 advances in the axial direction in conjunction with the movement of the piston rod 132 .

As in the second embodiment, the control by the second cylinder driving section 350 is configured so as to obtain a high driving force. Therefore, the second cylinder portion 330 advances the drive shaft 210 with a high driving force, and can normally drive the drive shaft 210 without stopping halfway even if an event that hinders the movement of the drive shaft 210 occurs. .

Next, the control unit 360 monitors the detection value from the rear second pressure sensor 52b, and determines whether or not the detection value of the rear second pressure sensor 52b is below a predetermined threshold value (step S505). . Specifically, the control unit 360 determines whether or not the internal pressure of the hydraulic oil in the rear second cylinder chamber 31b has decreased to a value sufficient to move the drive shaft 210 by the first cylinder unit 320. . As the predetermined threshold, for example, it may be set to a value corresponding to the supply pressure of the first direction control valve 341 (the upper limit of the pressure that can be supplied), or 90% (preferably may be set to a value of 80%).

When determined as NO in step S505, the control unit 360 determines whether or not the work is finished (step S552). If the determination in step S552 is YES, the control unit 360 terminates the control of the second cylinder driving unit 350. FIG. If NO is determined in step S552, the control unit 360 returns to step S505 and monitors the detection value of the second rear pressure sensor 52b again.

If the determination in step S505 is YES, the second cylinder driving section 350 closes the second direction control valve 351 (step S506). In step S506, the second direction control valve 351 is closed to maintain the internal pressures of the front side second cylinder chamber 31a and the rear side second cylinder chamber 31b, and the position of the piston rod 132 is fixed.

After the second directional control valve 351 is closed, the first cylinder driving section 340 drives the first cylinder section 320 again. That is, the control unit 360 moves the drive shaft 210 by operating the first direction control valve 341 via the first control valve amplifier 342 (step S507). As a result, the drive shaft 210 starts to move forward at high speed again.

Next, the control unit 360 determines whether or not the work has ended (step S508). If the determination in step S508 is YES, control unit 360 terminates the control of first cylinder drive unit 340. FIG. If NO is determined in step S508, the control unit 360 returns to step S502 and monitors the detection value of the first rear pressure sensor 51b again.

As described above, the cylinder-type actuator 300 of the present embodiment appropriately switches between control by the first cylinder driving section 340 capable of high-speed operation and control by the second cylinder driving section 350 capable of outputting a large driving force. , the drive shaft 210 can be moved at high speed or with a high driving force. In this embodiment, as in the first and second embodiments, the cylinder-type actuator 300 changes from the control by the first cylinder driving section 340 to the second cylinder driving section 340 regardless of the position of the drive shaft 210 . It is possible to switch to control by the unit 350 . Therefore, it is possible to switch to a movement having a high driving force not only at the initial movement of the drive shaft 210 but also at any timing during high-speed movement.

In this embodiment, regarding the operation of the cylinder type actuator 300, the case of moving the drive shaft 210 forward has been described, but it is also possible to move the drive shaft 210 backward by performing the same control. That is, when the drive shaft 210 is retracted, the first cylinder driving section 340 may supply hydraulic oil to the front first cylinder chamber 21a, and the control section 360 detects the detected value of the front first pressure sensor 51a. You should monitor. Further, the second cylinder drive section 350 may supply hydraulic oil to the front side second cylinder chamber 31a, and the control section 360 may monitor the detection value of the front side second pressure sensor 52a.

Each of the embodiments described above as embodiments of the present invention can be implemented in combination as appropriate as long as they do not contradict each other. Based on each embodiment, a person skilled in the art appropriately adds, deletes, or changes the design of components, or adds, omits, or changes the conditions of steps, and also includes the gist of the present invention. as long as it is within the scope of the present invention.

In addition, even if there are other effects that are different from the effects brought about by the aspects of each embodiment described above, those that are obvious from the description of this specification or those that can be easily predicted by those skilled in the art, Naturally, it is understood that it is brought about by the present invention.

Reference Signs List 10: Axial center 15, 16: Gap 20: Seal material 21a: Front first cylinder chamber 21b: Rear first cylinder chamber 30: Seal material 31a: Front second cylinder chamber 31b: Rear side second cylinder chamber 51a... Front side first pressure sensor 51b... Rear side first pressure sensor 52a... Front side second pressure sensor 52b... Rear side second pressure sensor 100... Cylinder type actuator 110 ... Drive shaft 110a ... Hollow part 120 ... First cylinder part 121 ... First cylinder 121a, 121b ... Lid part 121aa, 121ba ... Opening part 122 ... Screw shaft 123 ... Nut 130 ... Second cylinder Part 131 Second cylinder 131a, 131b Lid 131aa, 131ba Opening 132 Piston rod 132a Cylindrical part 132b Piston 140 First cylinder driving part 141 Power transmission Part 141a Drive side pulley 141b Driven pulley 141c Drive belt 142 Braking part 142a Electromagnetic coil 142b Spring 142c Brake disc 143 First motor 144 First motor amplifier , 150... Second cylinder drive unit 151... Pressure pump 152... Second motor 153... Second motor amplifier 160... Control unit 200... Cylinder type actuator 210... Drive shaft 220... First cylinder part , 221... First cylinder 221a, 221b... Lid part 221aa... Opening part 222... Piston 240... First cylinder driving part 241... Pressure pump 242... First motor 243... First motor amplifier, 244, 245... Direction control valve 260... Control part 300... Cylinder type actuator 320... First cylinder part 330... Second cylinder part 340... First cylinder drive part 341... First direction control valve 342 1st control valve amplifier 350 2nd cylinder drive unit 351 2nd directional control valve 352 2nd control valve amplifier 360 control unit

Claims (3)

a drive shaft;
a first cylinder portion for controlling axial advancement or retraction of the drive shaft;
a first cylinder driving section that operates the first cylinder section with rotational power ;
a second cylinder portion that controls the axial advancement or retraction of the drive shaft and the first cylinder portion using a working fluid;
a second cylinder driving section that operates the second cylinder section;
with
The first cylinder part includes a first cylinder in which part of the drive shaft is arranged,
the second cylinder section includes a second cylinder and a piston rod fixed to the front end of the first cylinder;
The drive shaft protrudes forward from inside the first cylinder, passes through the second cylinder and the piston rod, and protrudes forward beyond the second cylinder portion. The piston rod has a cylindrical portion penetrating the second cylinder, and an annular piston portion disposed along the outer circumference of the cylindrical portion and positioned inside the second cylinder,
The drive shaft penetrates the inner side of the tubular portion,
The inside of the second cylinder is divided into two second cylinder chambers by the cylindrical portion and the piston portion,
2. The method according to claim 1, wherein the second cylinder driving section controls the advancing or retreating of the piston rod in the axial direction by generating a pressure difference of the working fluid between the two second cylinder chambers. Cylinder type actuator as described. The first cylinder part includes the first cylinder, a threaded shaft penetrating through the rear end of the first cylinder and inserted into the first cylinder, and a screw shaft inside the first cylinder behind the drive shaft. a nut affixed to the end and threaded onto the threaded shaft;
a front end of the screw shaft is inserted into a hollow portion provided in the drive shaft;
3. The cylinder-type actuator according to claim 1, wherein said first cylinder part advances or retreats said nut and said drive shaft in said axial direction by rotating said screw shaft.

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