JPH11294553A - Electric actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric actuator that is able to make an actuating member to do its rectilinear movement as preventing its rotation in an accurate manner. SOLUTION: This electric actuator is on the precondition that rotation of a stepping motor 5 installed in an actuator body 2 is converted into a rectilinear motion, and in time of motor rotation, an actuating member 12 is rectilinearly shifted in the longitudinal direction. Then, it is provided with a guide rod 16 extending parallelly with this actuating member 12, connecting the actuating member 12 and the guide rod 16 to each other with a wear plate 19, whereby they are integrally moved. In addition, the actuating member 12 and ball bearings 15 and 18 corresponding to the guide rod 16 are installed in the actuator body 2 respectively, and the actuating member 12 and the guide rod 16 are slidably supported by both these bearings 15 and 18 in the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric actuator.

[0002]

2. Description of the Related Art Conventionally, various electric actuators are known as devices for converting a rotary motion into a linear motion.

[0003] The actuator body constituting such an electric actuator generally has a tubular shape.
A motor is attached to one end opening of the actuator body. The output shaft of the motor is arranged in a through hole of the actuator body. The output shaft of the motor and the feed screw portion are connected so as to be integrally rotatable by a coupling. In the through hole of the actuator body, a cylindrical operating member is housed so as to be able to protrude and retract. A work, which is a transferred object, can be attached to the front end of the operating member. A feed nut portion is fixed to the opening at the rear end of the operating member. A feed screw portion is screwed to the feed nut portion, and a power transmission mechanism that converts a rotational motion into a linear motion is configured by these two members.
On the inner peripheral surface of the actuator main body, a long groove for detent extending along the axial direction of the actuator main body is formed. Similarly, an engagement projection for preventing rotation is provided on the outer peripheral surface of the rear end portion of the operating member, and the engagement projection is slidably disposed in the long groove. In addition, as a technique of the same kind, there is a technique disclosed in, for example, Japanese Patent Publication No. 51-24663.

When the motor is driven to rotate in the prior art, the operation member moves linearly by the action of the power transmission mechanism. Further, when the operating member moves, the engagement protrusion engages with the long groove, so that the rotation of the operating member is prevented.

[0005]

However, since the rotation preventing mechanism of the prior art is a simple combination of the engaging projection and the long groove, the rotation of the operating member cannot be reliably prevented. Accordingly, there is a problem that the work is easily rotated, and as a result, it is difficult to carry out the work with high precision.
In addition, there was a problem that the ability to receive an eccentric load generated when the operating member was at the most advanced position was insufficient, so that it was not suitable for high-precision transport.

Here, it is considered that if the engaging projections and the long grooves constituting the simple rotation preventing mechanism are enlarged, the rotation preventing function can be improved to some extent. However, since the engagement protrusion and the long groove are located inside the through hole of the actuator main body in which the operation member and the like are accommodated, there is naturally a space limitation. As a result, there has been a situation in which the conveyance cannot be performed while securing sufficient accuracy.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric actuator capable of linearly moving an operating member while preventing it from rotating with high precision.

[0008]

According to the first aspect of the present invention, a rotary motion of a motor provided in an actuator body is converted into a linear motion, and an operating member is moved when the motor rotates. In the electric actuator that moves linearly in the longitudinal direction, the operating member is formed to be long in the linear moving direction, and the actuator body is provided with a long guide member extending parallel to the linear moving direction of the operating member, The actuating member and the guide member are integrally movably connected. The actuator body is provided with bearing members corresponding to the actuating member and the guide member, and the actuating member and the guide member are slidable in the longitudinal direction by the two bearing members. Supported.

By the above means, when the motor rotates, the operating member is linearly moved integrally with the guide member. The detent of the operating member is performed by the guide member,
Both the operating member and the guide member are supported by bearing members. As a result, the operation member is prevented from rotating with high accuracy, and the linear movement thereof is also accurate.

According to a second aspect of the present invention, in the electric actuator according to the first aspect, the converting means for converting the rotational motion of the motor into a linear motion is a feed screw which rotates integrally with the motor and is formed in an elongated shape. And a linear feed portion that is linearly moved with the rotation of the feed screw portion in a state where its rotation is prevented, and the feed screw portion is integrally rotatably connected to the output shaft of the motor, The linear feed portion is provided integrally with the operating member.

[0011] By the above means, the operation member is connected to the guide member to prevent the rotation of the operation member. Therefore, the linear feed portion provided integrally with the operation member is also prevented from rotating. As a result, when the feed screw portion rotates with the rotation of the motor, the linear feed portion moves linearly without rotating, whereby the operating member moves linearly. Therefore, not only can the structure be simplified by forming the conversion means with the feed screw portion and the linear feed portion, but also the rotation stop of the linear feed portion can be achieved by the presence of the guide member, so that the rotation preventing mechanism dedicated to the linear feed portion is provided. Is unnecessary, and the configuration is further simplified.

According to a third aspect of the present invention, in the electric actuator according to the second aspect, a receiving hole extending in a longitudinal direction of the operating member is formed inside the operating member, and a straight line is formed in an opening of the receiving hole. The leading end of the feed screw portion was housed in the housing hole in a state where the feed portion was integrally attached and the feed screw portion was screwed into the linear feed portion.

According to the above-mentioned means, since the leading end of the feed screw portion is housed in the housing hole formed in the operating member, the operating member functions as a protective material for the feed screw portion, and dust adheres to the feed screw portion. Is prevented as much as possible. As a result, it is possible to prevent malfunction due to dust adhesion. Another advantage is that the entire length of the electric actuator is shortened by accommodating the distal end portion of the feed screw portion in the accommodation hole formed in the operating member.

According to a fourth aspect of the present invention, in the electric actuator according to the second or third aspect, the center axis of the output shaft of the motor and the center axis of the feed screw portion are arranged on the same straight line, and And the proximal end of the feed screw portion were connected by coupling.

According to the above-mentioned means, since the center axis of the output shaft of the motor and the center axis of the feed screw portion are arranged on the same straight line, rotation can be transmitted from the output shaft to the feed screw portion only by the coupling. The simplification and downsizing of the configuration can be achieved as compared with the case where the two central axes are not on the same straight line.

According to a fifth aspect of the present invention, in the electric actuator according to any one of the first to fourth aspects, the connection between the operating member and the guide member is performed by connecting the tip portions of both to the same plate. It was done by doing.

By connecting the operating member and the guide member with the aforesaid plate by the above means, it becomes possible to attach a work or the like to the abutment plate. According to a sixth aspect of the present invention, in the electric actuator according to any one of the first to fifth aspects, the outer peripheral surface of the operating member and the outer peripheral surface of the guide member are configured to have circular cross sections. The two bearing members were each constituted by a ball bearing.

According to the above-described means, since a ball bearing which is a particularly high-precision bearing member among the bearing members is employed, the result is that the rotation of the operating member and the precision of the linear motion can be further enhanced.

According to a seventh aspect of the present invention, in the electric actuator according to the sixth aspect, the outer diameters of the outer peripheral surface of the operating member and the outer peripheral surface of the guide member are the same, and a common ball bearing is used.

According to the above means, a common ball bearing can be used for bearing the operating member and the guide member, so that the cost can be reduced by using common parts. According to the invention described in claim 8, claim 1 to claim 7 are provided.
In the electric actuator according to any one of the above, a piston is connected to the guide member, the piston is housed in a cylinder chamber provided in the actuator main body, and a thrust is applied to the guide member by supplying and discharging fluid to and from the cylinder chamber. It was configured to be able to occur.

By the above means, the guide member has a cylinder structure, so that even if the motor itself is small and has a small thrust, an auxiliary thrust on the guide member side is applied to obtain a sufficient thrust as a whole. be able to. As a result, there is no need to use a large motor.

According to a ninth aspect of the present invention, in the electric actuator according to any one of the first to eighth aspects, the actuator main body is formed as a single body. By the above means, not only the structure of the actuator body is simplified but also the positional relationship between the actuating member and the guide member, as compared with a structure in which the actuator body is divided into two parts on the operating member side and the guide member side. It can be firm and contributes to the highly accurate movement of the operating member.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an electric actuator will be described below with reference to FIG. The actuator main body 2 constituting the electric actuator 1 is a block-shaped unit having a substantially rectangular parallelepiped shape, and is integrally formed by, for example, aluminum extrusion. A first through-hole 3 and a second through-hole 4 are formed in the actuator body 2 so as to penetrate in the longitudinal direction and extend in parallel with each other. These two through holes 3 and 4 are formed to have the same inner diameter.

A stepping motor 5 as a drive source is fixed to the rear end face of the actuator body 2 corresponding to the rear end opening of the first through hole 3. The rear end opening of the first through hole 3 is closed by the stepping motor 5. The output shaft 6 of the stepping motor 5 has the first through hole 3
It is projected into.

The feed screw portion 7 is formed in an elongated shape so as to extend in the longitudinal direction of the first through hole 3, and is housed in the first through hole 3. As a material for forming the feed screw portion 7, a hard metal such as stainless steel is used. The front end side of the output shaft 6 and the rear end side of the feed screw portion 7 are connected by a coupling 8 as connecting means. The central axis of the output shaft 6 and the central axis of the feed screw portion 7 are arranged on the same straight line, and both are integrally rotated via the coupling 8. A screw thread 9 is formed on substantially the entire outer circumferential surface of the feed screw portion 7 in the longitudinal direction.

The feed nut portion 10 as a linear feed portion is accommodated in the first through hole 3. The outer diameter of the feed nut portion 10 is formed smaller than the inner diameter of the first through hole 3. The feed nut portion 10 is formed with a screw hole 11 having the same pitch as the screw thread 9 and screwed to the feed screw portion 7. The feed screw portion 7 and the feed nut portion 10 constitute a conversion unit.

The operating member 12 is formed in an elongated shape so as to extend in the longitudinal direction of the first through hole 3, and is housed in the first through hole 3. The distal end side of the operating member 12 protrudes from the distal end surface of the actuator body 2. The operating member 12 is formed of a hard metal material such as stainless steel. An accommodating hole 13 extending in the longitudinal direction is formed in the operating member 12, and the accommodating hole 13 is opened at a rear end surface of the operating member 12. The distal end side of the feed screw portion 7 is inserted into the accommodation hole 13. A feed nut 10 is fixed to the rear end of the operating member 12 so as to close the opening of the receiving hole 13, and the feed nut 10 and the operating member 12 are integrally formed.

A cylindrical cover 14 is fixed to the actuator body 2 at a position corresponding to the tip end of the first through hole 3. The cover 14 is fixed by setting the front end side of the first through hole 3 to a large diameter 3a and forming a step 3b in the middle of the first through hole 3.
After the cover 14 is inserted from the distal end face side of the actuator body 2 to the step 3b, an engaging member such as a C-ring is attached to the actuator body 2, and the cover 14 is attached to the step 3b and the C-ring or the like. It is performed by pinching. The operating member 12 is inserted through the cover 14. The cover 14 is provided with a ball bearing 15 as a bearing member, and the outer peripheral surface of the operating member 12 is supported with high precision by the ball bearing 15.

The guide rod 16 as a guide member is formed in a long shape so as to extend in the longitudinal direction of the second through hole 4, and is housed in the second through hole 4. The distal end side of the guide rod 16 projects from the distal end surface of the actuator body 2. The guide rod 16 is formed of a hard metal material such as stainless steel. The outer diameter of the guide rod 16 is formed so as to match the outer shape of the operating member 12.

A cylindrical rod-side cover 17 is fixed to the actuator body 2 at a position corresponding to the tip end of the second through hole 4. The fixing of the rod side cover 17 is performed in the same manner as the cover 14. That is, a step portion 4b is formed in the middle of the first through hole 4 with the front end side of the second through hole 4 as a large diameter 4a, and the rod side cover 17 is inserted from the front end surface side of the actuator body 2 to the step portion 4b. After that, the engaging member such as the C-ring is
On the rod side cover 1 with the stepped portion 4b and C-ring etc.
7 is carried out. Guide rod 1
6 is inserted into the rod side cover 17. The rod-side cover 17 is provided with a ball bearing 18 as a bearing member, and the outer peripheral surface of the guide rod 16 is supported with high precision by the ball bearing 18. The rod-side cover 17 has basically the same configuration and the same size as the cover 14, and the same ball bearings 15 and 18 are used.

The tip of the operating member 12 and the guide rod 16
A contact plate 19 is fixed to the tip of. The fixing is performed, for example, by tightening bolts 20. Therefore, since the guide rod 16 is connected to the operating member 12 via the contact plate 19, the guide rod 16 is
Functions as a detent means. Since the operating member 12 and the feed nut portion 10 are integrally formed, the guide rod 16 also functions as a detent means for the feed nut portion 10. Therefore, when the feed screw portion 7 rotates,
The feed nut portion 10 is connected to the feed screw portion 7 in accordance with the rotation direction.
Is moved back and forth along the longitudinal direction of. At the same time, the operating member 12 is advanced and retracted in the longitudinal direction. At the same time, the plate 19 and the guide rod 16 are moved forward and backward in the same direction.

A head side cover 21 is fixed to the actuator body 2 so as to close the base end of the second through hole 4. A piston 22 is accommodated in the second through hole 4 between the rod-side cover 17 and the head-side cover 21. The base end of the guide rod 16 is fixed to the piston 22.

A seal ring 23 for sealing with the actuator body 2 is mounted on the outer peripheral surface of the rod-side cover 17, the outer peripheral surface of the head-side cover 21, and the outer peripheral surface of the piston 22. A rod packing 24 for sealing with the guide rod 16 is mounted on the inner peripheral surface of the rod side cover 17. Therefore, the rod-side cover 17 and the head-side cover 21 in the second through hole 4
Is a hermetically sealed area, that is, a cylinder chamber. The cylinder chamber is divided into a rod-side cylinder chamber 25 and a head-side cylinder chamber 26 by a piston 22.

A first port 27 communicating with the rod-side cylinder chamber 25 and a second port 28 communicating with the head-side cylinder chamber 26 are juxtaposed on a side surface of the actuator body 2 adjacent to the second through hole 4. ing.

A rubber cushion ring 29 is mounted on the distal end surface of the piston 22. Cushion ring 2
Numeral 9 is provided for determining the stop position when the operating member 12 and the guide rod 16 are arranged at the foremost end position and for reducing the impact, and functions as a stopper at the foremost end position and cushions. Also functions as a member.

A cushion rubber 19a is mounted between the operating member 12 and the guide rod 16 on the rear end surface of the contact plate 19. A stopper bolt 3 is provided on the tip end surface of the actuator body 2 so as to face the cushion rubber 19a.
0 is attached. The stopper bolt 30 is the operating member 1
When the guide rod 2 and the guide rod 16 are arranged at the rearmost position, they come into contact with the cushion rubber 19a to determine the stop position, and function as stoppers at the rearmost position.

A permanent magnet 31 is mounted on the outer peripheral surface of the piston 22 as a magnet generating means. The permanent magnet 31 is provided for detecting the position of the piston 22 by a position detecting device (not shown) mounted on the actuator body 2.

In the actuator body 2, mounting holes 32 are formed at a plurality of locations between the first through hole 3 and the second through hole 4 so as to pass therethrough. In the present embodiment, the mounting holes 32 are formed at two places apart from each other. The mounting hole 32 is provided so that a bolt or the like is inserted therein and can be used when fixing the actuator main body 2 at a predetermined position.

Next, the operation of the electric actuator 1 configured as described above will be described. In the initial state before the stepping motor 5 is energized, the stopper bolt 30 is in contact with the distal end surface of the actuator body 2 as shown in FIG. At this time, it is assumed that the operating member 12, the guide rod 16, and the abutment plate 19 are at the rearmost position, that is, the origin position.

When the stepping motor 5 is driven in one direction by starting energization, the output shaft 6 and the feed screw 7 connected thereto are integrally rotated in one direction (forward direction). Feed nut part 1 which is screwed with feed screw part 7
0 moves forward along the longitudinal direction of the feed screw portion 7 because the rotation is stopped by the rotation stopping function of the guide rod 16. Accordingly, the operating member 12, the abutment plate 19, and the guide rod 16 provided integrally with the feed nut portion 10 advance integrally.

When the operating member 12 reaches the frontmost position, the cushion ring 29 is moved to the rod-side cover 1.
7 comes into contact with the rear end face. As a result, further advancement of the operating member 12 and the like is restricted, and the impact at the time of stopping is reduced.

Thereafter, when the stepping motor 5 is driven in the other direction (in the opposite direction), the output shaft 6 and the feed screw portion 7 connected thereto are integrally rotated in the opposite direction, which is the opposite direction. At this time, the feed nut portion 10, the operating member 12, the abutment plate 19, and the guide rod 16 integrally move backward.

When the operating member 12 reaches the rearmost position, the head of the stopper bolt 30 contacts the cushion rubber 19a. As a result, further backward movement of the operating member 12 and the like is restricted, and the impact at the time of stopping is reduced.

Here, the first port 27 and the second port 2
8 can be used as supply / discharge ports for supplying / discharging fluid, respectively. When the stepping motor 5 is energized to advance the operating member 12, the abutment plate 19 and the guide rod 16, the fluid is supplied to the second port 28 and the fluid is discharged from the first port 27. . On the other hand, when the operation member 12, the abutment plate 19 and the guide rod 16 are moved backward by energizing the stepping motor 5, the fluid is supplied to the first port 27 and the fluid is discharged from the second port. Thus, the operating member 12 and the like are advanced and retracted in a state where the thrust in the traveling direction is added to the piston 22 in addition to the rotational force of the stepping motor 5.

When the auxiliary thrust is unnecessary, the first and second ports 27 and 28 can be opened to the atmosphere so that the rod-side cylinder chamber 26 and the head-side cylinder chamber 26 function as pressure chambers. And the forward and backward movement of the operating member 12 is not hindered.

Therefore, according to the present embodiment, the following effects can be obtained. (1) The rotation of the operation member 12 is stopped by the guide rod 16, and both the operation member 12 and the guide rod 16 are supported by ball bearings 15 and 18. As a result, the rotation of the operating member 12 is prevented with high precision, and the linear movement thereof is also performed with high precision.

(2) Since the operating member 12 is connected to the guide rod 16 to prevent rotation of the operating member 12, the feed nut portion 10 provided integrally with the operating member 12 is provided.
The rotation is also prevented. As a result, when the feed screw portion 7 rotates with the rotation of the stepping motor 5, the feed nut portion 10 moves linearly without rotating, whereby the operating member 12 moves linearly. Therefore, the conversion means is constituted by the feed screw portion 7 and the feed nut portion 10, so that not only the structure can be simplified, but also the rotation of the feed nut portion 10 is achieved by the presence of the guide rod 16, so that the feed nut portion 10 is provided. A dedicated rotation preventing mechanism is not required, and the configuration can be further simplified.

(3) The tip of the feed screw 7 is the operating member 1
Since the operation member 12 is accommodated in the accommodation hole 13 formed in the feed screw 2, the actuating member 12 functions as a protective material for the feed screw portion 7, and dust is prevented from adhering to the feed screw portion 7 as much as possible. As a result, it is possible to prevent malfunction due to dust adhesion. In addition, the leading end of the feed screw portion 7 has a receiving hole 1 formed in the operating member 12.
3 has the advantage that the total length of the electric actuator 1 is reduced.

(4) Since the center axis of the output shaft 6 of the stepping motor 5 and the center axis of the feed screw portion 7 are arranged on the same straight line, the output shaft 6 rotates from the output shaft 6 to the feed screw portion 7 with only the coupling 8. Since transmission can be performed, simplification and downsizing of the configuration can be achieved as compared with the case where the two central axes are not on the same straight line.

(5) Since the connection between the operating member 12 and the guide rod 16 is performed by connecting the ends of both to the same abutment plate 19, it is possible to attach a work or the like to the abutment plate 19. .

(6) Operating member 12 and guide rod 16
Since the ball bearings 15 and 18, which are particularly high-precision bearing members, are employed for bearings, the rotation of the operating member 12 and the precision of linear motion can be further promoted.

(7) When the outer diameter of the outer peripheral surface of the operating member 12 and the outer diameter of the outer peripheral surface of the guide rod 16 are made the same, the ball bearings 15 and
Since 18 is common, cost can be reduced by sharing parts.

(8) Since the guide rod 16 side has a cylinder structure, even if the stepping motor 5 itself is small and has a small thrust, the auxiliary thrust generated on the guide rod side is applied, so that the whole is sufficient. High thrust can be obtained. As a result, the large stepping motor 5
Eliminates the need to use

(9) Since the actuator body 2 is formed as a single unit, the structure of the actuator body 2 can be simplified as compared with a structure in which the actuator body is divided into the operating member 12 and the guide rod 16 in two. In addition to the connection, the positional relationship between the operating member 12 and the guide rod 16 can be made firm, which contributes to the highly accurate movement of the operating member 12.

(10) Since the permanent magnet 31 is provided on the piston 22 and the position detecting device is provided on the actuator body 2, the operating member 12 is actuated by a detection signal from the position detecting device.
Can be detected. Since the position detection is performed in a non-contact manner, the operation of the operation member 12 is not adversely affected.

(11) Since the cushion ring 29 and the stopper bolt 30 for determining the most advanced end position and the most advanced end position of the operating member 12 are provided, the most advanced end position and the most advanced end position of the operating member 12 are determined. The determination can be made without depending on the control of the stepping motor 5.

In addition to the embodiment described above, there are other embodiments as follows. -As shown in FIG. 2, the guide rod 16 may be configured as a simple rod. In this case, the guide rod 1
The cover 14 which is completely the same as the operation member 12 on the side 6
And the ball bearing 15 can be used. In this case, the structure can be extremely simplified as compared with the above embodiment.

The operating member 12 and the guide rod 16 are not limited to stainless steel, and may be made of a material harder than at least aluminum. When using a metal material that is softer than or equal to aluminum, the rigidity of the operating member 12 and the guide rod 16 themselves is not maintained, and the ball bearing 1
This is because high-precision linear motion cannot be secured by 5, 18. Materials other than stainless steel include, for example, other metal materials such as steel materials and ceramic materials.

A bearing member such as a resin bush other than the ball bearings 15 and 18 may be used. However, ball bearing 1
It is better to use the operating member 12 and the guide rod 1
6 highly accurate linear motions are achieved. Of course, only one of the two ball bearings 15, 18 may be configured as another bearing member.

Instead of the combination of the guide rod 16 and the ball bearing 18, a combination of a guide block and a guide rail may be used. It is not essential that the outer peripheral surfaces of the actuating member 12 and the guide rod 16 have a circular cross section, but may have another shape such as a triangular cross section or a spline structure.

The position of the operating member 12 may be detected indirectly by detecting the direction and amount of rotation of the motor instead of detecting the piston position.
Further, a magnet may be attached to the feed nut portion 10 and the magnetism may be detected. That is, the position of a member that operates in association with the operating member 12 may be detected.

The conversion means includes a feed screw portion 7 having a thread 9 and a feed nut portion 10 having a screw hole 11.
And made mechanical screw connection,
The feed screw portion 7 may be a magnetic screw, and a linear feed portion that is magnetically coupled to the magnetic screw and can perform a linear motion may be provided instead of the feed nut portion 10.

Means other than the claims and their effects, which are grasped by the embodiments described above, are listed below. (1) In any one of the first to ninth aspects, there is provided a position detecting means for detecting a moving position of the operating member and the guide member. According to this means, the moving position of the operating member can be accurately grasped.

(2) In the above means (1), the position detecting means detects the magnetism of the magnetic generating means provided on the guide member. According to this means, since the position of the operating member can be indirectly detected, the operation of the operating member is not adversely affected, and the piston position detecting device used for the fluid pressure cylinder can be used. It also leads to cost reduction.

(3) In any one of the first to ninth aspects, a stopper is provided for regulating the backward movement of the operating member at a predetermined position. According to this means, the most advanced position of the operating member can be determined without depending on the control of the motor.

(4) In the above means (3), a stopper is provided on at least one of the abutment plate and the surface of the actuator body opposed thereto, and the reverse movement of the operating member is regulated by the abutment of the stopper against the other. . According to this means, the stopper can be installed by utilizing the space between the abutment plate and the actuator body, and the size of the device due to the stopper can be prevented.

(5) In any one of the first to ninth aspects, a stopper (piston or cushion ring) for restricting the advance of the operating member at a predetermined position is provided. According to this means, the most advanced position of the operating member can be determined without depending on the control of the motor. When the stopper is made of a rubber member, a cushion effect can be obtained at the same time.

[0068]

As described above in detail, according to the first aspect of the present invention, the rotation of the operating member can be stopped by the guide member which moves integrally with the operating member.
Since both the operating member and the guide member are supported by the bearing member, it is possible to realize a highly accurate rotation stop of the operating member, and also to make the linear movement highly accurate.

According to the second aspect of the present invention, the conversion means for converting the rotary motion into the linear motion is constituted by the feed screw portion and the linear feed portion. Since rotation prevention is also achieved by the presence of the guide member, a rotation prevention mechanism dedicated to the linear feeder is not required, and the configuration can be further simplified.

According to the third aspect of the present invention, since the leading end of the feed screw portion is housed in the housing hole formed in the operating member, the operating member functions as a protective material for the feed screw portion, Dust adheres to the thread as much as possible,
It is possible to prevent malfunction due to dust adhesion.
In addition, since the leading end of the feed screw portion is housed in the housing hole formed in the operating member, the overall length of the electric actuator is shortened.

According to the fourth aspect of the present invention, the center axis of the output shaft of the motor and the center axis of the feed screw portion are arranged on the same straight line, so that only the coupling is used to move the output shaft from the output shaft to the feed screw portion. Since rotation can be transmitted, simplification and downsizing of the configuration can be achieved as compared with the case where the two central axes are not on the same straight line.

According to the fifth aspect of the present invention, by connecting the operating member and the guide member with the abutment plate, it becomes possible to attach a work or the like to the abutment plate. According to the invention as set forth in claim 6, since the ball bearing which is a particularly high-precision bearing member among the bearing members is employed, it is possible to further promote the prevention of the rotation of the operating member and the higher precision of the linear motion.

According to the seventh aspect of the present invention, since a common ball bearing can be used for bearing the operating member and the guide member, the cost can be reduced by using common components.

According to the eighth aspect of the present invention, since the guide member has a cylinder structure, even if the motor itself is small and has a small thrust, an auxiliary thrust on the guide member side is applied to the motor as a whole. Since sufficient thrust can be obtained, it is not necessary to use a large motor.

According to the ninth aspect of the present invention, not only is the structure of the actuator main body divided into two parts on the operating member side and the guide member side, but also the structure of the actuator main body is simplified, The positional relationship between the operating member and the guide member can be made firm, which contributes to the highly accurate movement of the operating member.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an electric actuator.

FIG. 2 is a sectional view showing another embodiment of the electric actuator.

[Explanation of symbols]

1: electric actuator, 2: actuator body, 3
1st through hole, 4 2nd through hole, 5 ... stepping motor as motor, 6 ... output shaft, 7 ... feed screw part forming conversion means, 8 ... coupling, 10 ... straight line forming conversion means A feed nut portion as a feed portion, 12 an operating member, 13 an accommodation hole, 15 a ball bearing as a bearing member, 16 a guide rod as a guide member, 18 a ball bearing as a bearing member, 19 a corresponding plate, 22: piston, 25: rod-side cylinder chamber forming a cylinder chamber,
26 ... Cylinder chamber on the head side constituting the cylinder chamber.

Claims (9)

[Claims] 1. An electric actuator for converting a rotational movement of a motor provided on an actuator body into a linear movement and linearly moving an operating member in a longitudinal direction when the motor rotates, wherein the operating member is elongated in the linear moving direction. The actuator body is provided with a long guide member extending parallel to the linear movement direction of the operating member, and the operating member and the guide member are integrally movably connected to each other. An electric actuator in which bearing members are provided corresponding to the members, and the operating member and the guide member are slidably supported in the longitudinal direction by the two bearing members. 2. The electric actuator according to claim 1, wherein the converting means for converting the rotational motion of the motor into a linear motion is provided with a feed screw portion formed integrally with the motor and having a long shape, and a rotation of the feed screw portion. A linear feed portion that is moved linearly with the rotation of the feed screw portion in the blocked state, and the feed screw portion is connected to the output shaft of the motor so as to be integrally rotatable, and the linear feed portion is connected to the operating member. An electric actuator provided integrally. 3. The electric actuator according to claim 2, wherein an accommodating hole extending in a longitudinal direction of the actuating member is formed inside the operating member, and a linear feed portion is integrally attached to an opening of the accommodating hole. An electric actuator in which the leading end of the feed screw portion is housed in the housing hole in a state where the feed screw portion is screwed into the linear feed portion. 4. The electric actuator according to claim 2, wherein a central axis of an output shaft of the motor and a central axis of the feed screw portion are arranged on the same straight line, and a tip end portion of the output shaft and a feed screw portion. Electric actuator in which the base end of the actuator is connected by a coupling. 5. The electric actuator according to claim 1, wherein the connection between the operating member and the guide member is performed by connecting both ends of the guide member to the same plate. . 6. The electric actuator according to claim 1, wherein the outer peripheral surface of the operating member and the outer peripheral surface of the guide member are configured to have a circular cross-sectional shape. Are electric actuators each constituted by a ball bearing. 7. The electric actuator according to claim 6, wherein the outer peripheral surface of the operating member and the outer peripheral surface of the guide member have the same outer diameter, and a common ball bearing is used. 8. The electric actuator according to claim 1, wherein a piston is connected to the guide member, the piston is housed in a cylinder chamber provided in the actuator body, and a fluid is provided in the cylinder chamber. An electric actuator configured to generate thrust in the guide member by supplying and discharging the electric power. 9. The electric actuator according to claim 1, wherein the actuator main body is formed as a single body.