JPH10127008A - Electric cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric cylinder, which can have a sufficient back and forth stroke when used in a narrow space after its size is reduced and the thickness of a body case is lessened as thin as possible, and which can be assembled and manufactured easily at low cost. SOLUTION: An electric cylinder 1 has such a mechanism that a screw lever 8 is rotated by an electric motor 5 through a speed reduction mechanism 2 to move a piston 7 back and force which is screwed on the screw lever 8. A body case 3 for storing the speed reduction mechanism 2 is constituted of a lower case 3a formed in a bowl-shaped storing section 3c having an installation section 30 on its other side face, and a flat case cover 3b for closing and fixing an opening of the lower case 3a. With a cylinder section 6 and the electric motor 5 integrally fastened on the surface of the case cover 3b, a pinion gear 20 provided in the electric motor 5 and a flat gear 21 provided on the screw lever 8 are engaged with each other to constitute the single speed reduction mechanism 2. The speed reduction mechanism 2 is housed in the lower case 3a having the storing section 3c which is formed in such a depth as to store the flat gear 21, and the lower case 3a is closed by the case cover 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric cylinder which rotates a screw rod of a cylinder section from an electric motor via a speed reduction mechanism to move a piston forward and backward.

[0002]

2. Description of the Related Art Conventionally, an electric cylinder as an electric actuator as described above has a main body case divided into an upper case and a lower case by a casting die, and an electric motor and a cylinder cylinder are erected. The upper case is formed as a bowl-shaped storage portion having a depth that accommodates a multi-stage type speed reduction mechanism in which a large number of gears are meshed in a plurality of stages to reduce the speed in a plurality of stages. The lower portion is configured to be closed and fixed by a lower case in which a mounting portion for the mounting member is formed to protrude below the mounting member.

[0003]

SUMMARY OF THE INVENTION In the electric cylinder having the above-mentioned conventional construction, the main body case, in which the multi-stage type reduction mechanism in which the gears are meshed in a plurality of stages in the vertical direction, is bulky and the case thickness becomes large. Therefore, when the electric cylinder is interposed between the mounting member side and the operating member side operated by the piston and used to move forward and backward between them, it is not possible to take a sufficient stroke for the forward and backward operation due to the thickness of the main body case. And the like. Also, the main body case containing the multi-stage speed reduction mechanism requires fitting means such as high-precision machining for mounting and fixing the cylinder cylinder to the upper case made of casting,
In order to fit the metal of the plurality of rotating shafts that support the gears in the upper and lower cases, the machining operation such as requiring precise machining is complicated, and the lower case is formed with a mounting portion for the mounting member. Therefore, there is a problem that a plurality of casting molds are required for each of the upper case and the lower case, and the manufacturing cost is increased.

[0004]

In order to solve the above-mentioned problems, the electric cylinder according to the present invention rotates the screw rod 8 from the electric motor 5 via the speed reduction mechanism 2 and engages with the screw rod 8. In the electric cylinder 1 that moves the piston 7 forward and backward,
A lower case 3a in which a main body case 3 accommodating the speed reduction mechanism 2 is formed in a bowl-shaped storage portion 3c having a mounting portion 30 on the other side, and a flat case lid for closing and fixing an opening of the lower case 3a. 3c, and a pinion gear 20 and a screw rod 8 provided on the electric motor 5 in a state where the cylinder portion 6 and the electric motor 5 are integrally fixed on the surface of the case lid 3c.
And a flat gear 21 provided in the lower case 3a. The lower gear 3 is provided in a lower case 3a in which a storage portion 3c is formed at a storage depth of the flat gear 21. The storage is closed at 3b.

Second, a cylinder cylinder 60 is attached to the case lid 33a.
Is welded at its base end and fixed upright.

Third, the shaft end of the screw rod 8 is connected to the lower case 3a.
Are supported by bearings 33 that are fitted and supported on the inner surface facing the mounting portion 30.

[0007]

An embodiment of the present invention will be described with reference to the drawings. An electric actuator (electric cylinder) 1 shown in FIG. 1 is interposed between the mounting member A side and the operating member B side and moves forward and backward between the two.
A body case 3 containing a one-stage reduction mechanism 2 described below
An electric motor 5 is mounted and fixed, and a cylinder portion 6 that is operated from the electric motor 5 via the speed reduction mechanism 2 is provided upright. A mounting hole (mounting portion) formed in a head of a piston 7 of the cylinder portion 6 is formed. ) 70 and the operating member B are connected via the mounting pin 71, and the mounting hole 31 of the mounting portion 30 protruding from the bottom of the main body case 3 at a portion facing the mounting member B is connected to the mounting member A by the mounting pin 32. Used to be installed.

In this embodiment, the main body case 3 is composed of a lower case 3a and an upper case (case lid) 3b. The lower case 3a is open at the upper side and accommodates a single-stage reduction mechanism 2 by meshing with a flat gear. The storage portion 3c having a depth to be formed is formed of an aluminum casting into a bowl shape and the mounting portion 30 is integrally formed, and the case lid 3b is formed by punching a flat iron plate into the same shape as the opening. The lower end of a cylinder cylinder (outer cylinder) 60 of the cylinder section 6 is welded and fixed to the center thereof, and the drive shaft 50 of the electric motor 5 is fixed.
Are formed, and a screw hole 51a for mounting is formed, and the electric motor 5 is mounted with the mounting screw 3M. Then, in a state where the upward opening of the storage portion 3c of the lower case 3a is closed by the case lid 3b, both are closed and fixed so as to be openable and closable by the mounting screw 3N.

In this state, a bearing (metal) 33 fitted and supported in a portion facing the mounting portion 30 in the lower case 3a, and the cylinder cylinder 6 of the case lid 3b.
The lower part of the screw rod 8 is supported by a bearing 33a supported at the lower end, and a screw part 80 is provided in the cylinder cylinder 60.
Are formed to the same length and are erected. In the case cover 3b, a drive shaft 5 is inserted into a long hole or a through hole 51 formed in a stupid hole.
In a state where 0 is inserted, the electric motor 5 is fastened and fixed by inserting the mounting screw 3M into the screw hole 51a.

The speed reduction mechanism 2 is connected to the drive shaft 50.
A pinion gear 20 is attached to the spur gear 2, and the pinion gear 20 is attached to the screw rod 8 between the bearings 33 and 33a.
1 to form a compact reduction gear mechanism that performs one-step reduction of the spur gear mesh, so that the thickness of the main body case 3 can be made as thin as possible. , Mounting member A and operating member B
When the electric cylinder 1 is installed within the restricted distance between the electric cylinder 1 and the electric cylinder 1, a predetermined reciprocating stroke can be sufficiently obtained and the operating member B can be appropriately operated.

On the other hand, the cylinder portion 6 has a sliding metal 61 integrally formed on the upper end of a cylinder cylinder 60 to slidably support the outer periphery of the piston 7 and is integrally attached to the lower end of the piston 7. The screw cylinder 75 is screwed into the screw rod 8. Also, an upper concave groove 72 is formed in the outer periphery below the mounting hole 70 above the piston 7, and a lower concave groove 73 is formed in the upper outer periphery of the screw cylinder 75 below. At the upper end, upper and lower contacts urged in the protruding direction are fixed via a mounting cover 92 with a limit switch 9 having 90 and 91, and the harness 93 is connected to the electric motor 5 to connect the upper and lower stroke ends of the piston 7. The control mechanism 9S is configured to stop the positioning.

In the electric cylinder 1 of the present invention having the above structure, when the piston 7 is lowered to the lower limit position as shown by the solid line in FIG. The electric motor 5 is maintained in a stopped state by protruding into the groove 72, and when the operation switch provided on the electric motor 5 is then turned up, the electric motor 5 rotates forward and is screwed via the speed reduction mechanism 2. The rod 8 is driven to rotate, and the piston 7 screwed with the rod 8 can be moved upward (extended) upward. When the piston 7 moves to the upper limit position, the lower concave groove 73 is exposed from the cylinder cylinder 60, so that the lower contact 91 of the limit switch 9 slidably in contact with the outer periphery of the piston 7 protrudes into the lower concave groove 73. , OF
Since the F signal is sent to the electric motor 5 and stopped, the further advance can be properly prevented.

In this state, when the operation switch 95 is operated to reverse the electric motor 5, the piston 7 can be moved backward through the speed reduction mechanism 2 and the screw rod 8, and the stroke end thereof is the same as described above. When the upper contact of the limit switch 9 is located in the upper concave groove 72, the operation of the electric motor 5 can be stopped. Therefore, the operation of the operation member B can be performed smoothly.
Incidentally, the operation stop within the stroke can stop the piston 7 in place by stopping the operation of the operation switch.

In manufacturing the electric cylinder 1, the flat case lid 3b can be easily formed by press-punching an iron plate, and the cylinder cylinder 60 can be efficiently joined to the case lid 3b by a simple butt welding means. After being fixed firmly and firmly, the electric motor 5 is fixed to the case lid 3b in advance in the same direction as the cylinder cylinder 60, and the speed reduction mechanism 2 is assembled in an assembling manner. It can be assembled so as to be housed in the mold-shaped housing portion 3c.

By adopting such an assembling means,
The speed reduction mechanism 2 is exposed on the rear side of the case lid 3b, and the operation of adjusting the meshing between the pinion gear 20 and the spur gear 21 is performed through the through hole 51 and the screw hole 51a of the electric motor 5 having the pinion gear 20. There is an advantage that the fixation can be performed easily and accurately by visually fixing to the appropriate meshing position. Although the case lid 3b formed in a flat shape has insufficient rigidity itself, it has sufficient rigidity when attached to the lower case 3a, so that the case lid 3b is deformed even when a load is applied when the electric cylinder 1 is operated. It can operate at high performance without doing anything. Therefore, the assembling and manufacturing of the electric cylinder 1 can be made inexpensive, and can be performed efficiently and easily.

The lower case 3a is not limited to the above-described embodiment. For example, as shown in FIG. 5, the lower case 3a of the main body case 3 may be formed by drawing using an iron plate. The lower case 3a of the illustrated example has a support part 33 for fitting and supporting the storage part 3c for housing the speed reduction mechanism 2 and the bearing 33.
b is formed by a single drawing die, and a U-shaped attachment portion 30 is welded and fixed to the outer surface of the support portion 33b. The lower case 3a
The electric cylinder 1 using the same has the same advantages as the above-described embodiment, and further has features such as further reduction in weight and improvement in mass productivity.

[0017]

According to the present invention constructed as described above, the cylinder cylinder can be simply and rigidly fixed to the flat case lid, and the electric motor is previously mounted on the case lid in the same direction. After assembling and properly adjusting the meshing with the one-stage reduction mechanism exposed on the back side of the case lid, the assembly is made into an assembly shape, and then the lower case with the bowl-shaped storage section is assembled, The work of assembling and manufacturing the cylinder can be performed easily and inexpensively. In addition, by using a single-stage reduction mechanism in which the pinion gear on the electric motor side and the flat gear on the screw rod side engage with each other, the size of the device is reduced and the thickness of the main body case is made as thin as possible. As a result, while the overall length of the electric cylinder can be shortened, a sufficient reciprocating operation stroke can be obtained even when used in a small place, so that it can be used effectively and conveniently.

At this time, the cylinder cylinder can be easily and rigidly fixed to the case lid by welding means, and the shaft end of the screw rod is supported in the thick mounting portion, so that the screw rod is supported. There is an advantage that the support of the electric cylinder can be favorably performed, and the total length of the electric cylinder can be shortened.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall structure of the device of the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a plan view of a cylinder unit of FIG. 2;

FIG. 4 is a plan view of a lower case.

FIG. 5 is a side sectional view showing a configuration of a main part of an electric cylinder according to another embodiment.

FIG. 6 is a plan view of the lower case of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric cylinder 2 Reduction mechanism 3 Main case 3a Lower case 3b Case lid (upper case) 3c Storage part 5 Electric motor 6 Cylinder part 7 Piston 8 Screw rod 30 Mounting part 33, 33a Bearing 20 Pinion gear 21 Flat gear 51 Through hole 51a Screw Hole 60 Cylinder cylinder A Mounting member B Operating member

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[Procedure amendment]

[Submission date] December 16, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall structure of the device of the present invention.

FIG. 2 is a side sectional view of FIG.

FIG. 3 is a plan view of a cylinder unit of FIG. 2;

FIG. 4 is a plan view of a lower case.

[5] (A) is a side sectional view showing a main portion of the electric cylinder according to another embodiment. (B) is below (A)
It is a top view of a part case.

Claims (3)

[Claims] An electric cylinder (1) that rotates a screw rod (8) from an electric motor (5) via a speed reduction mechanism (2) and moves a piston (7) screwed into the screw rod (8) forward and backward. 1)
And a lower case (3a) in which a main body case (3) for housing the speed reduction mechanism (2) is formed in a bowl-shaped storage portion (3c) having a mounting portion (30) on the other side surface; 3a) and a plate-like case lid (3c) for closing and fixing the opening, wherein the cylinder (6) and the electric motor (5) are integrally fixed to the surface of the case lid (3c). , A pinion gear (20) provided on an electric motor (5)
And a spur gear (21) provided on the screw rod (8) to form a one-stage speed reduction mechanism (2). The speed reduction mechanism (2) is stored in the storage portion at the storage depth of the flat gear (21). Case cover (3b) installed in lower case (3a) formed with (3c)
An electric cylinder that is housed and closed. 2. A cylinder cylinder (6) is attached to the case lid (33a).
2. The electric cylinder according to claim 1, wherein the base is welded at its base end and fixed upright. The shaft end of the screw rod (8) is connected to the lower case (3).
3. The electric cylinder according to claim 1, wherein the electric cylinder is supported by a bearing (33) fitted and supported on an inner surface facing the mounting portion (30) of (a).