JPH0113879Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is useful, for example, when automatically opening/closing a door attached to an enclosure built around a mechanical device in order to ensure safety in a machining center, and in other types of movable applications. An actuator used to reciprocate a member between two positions. Specifically, a piston fitted in a cylinder is driven reciprocally in the cylinder axis direction by controlling the supply of fluid pressure to the cylinder chamber on both sides of the piston. A driven body is configured to be movable and can be reciprocated along a fixed path parallel or substantially parallel to the cylinder axis direction on the outside of the cylinder, and between the driven body and the piston, The present invention relates to a reciprocating actuator that uses a fluid pressure cylinder and is provided with a moving force transmission mechanism that transmits the reciprocating force of the piston to the driven body.

<Prior art> The actuator with the above configuration has a rodless cylinder as its main configuration, which not only reduces the cylinder bore diameter but also overlaps the range of reciprocating movement of the driven body within the axial length range of the cylinder to achieve a predetermined stroke. It has practical effects such as being able to reduce the space occupied by the actuator required to perform the reciprocating motion of the actuator, increasing the output/weight ratio and the force/magnitude ratio, and greatly widening the versatility.

By the way, heretofore known actuators that use this kind of rodless cylinder are: (a) As schematically shown in FIG. A moving force transmission mechanism 04 that transmits a moving force to a driven body 03 that is reciprocally movable includes a wire that is endlessly looped and connected between both side surfaces of the piston 02 in the movement direction, in a state that includes the moving path of the driven body 03. (b) Although not shown in the drawings, there are two types of wires: one constructed using a flexible steel strip instead of the wire.

<Problems to be solved by the invention> However, in the conventional actuator with the above configuration, although there are advantages and disadvantages when comparing the former (a) and the latter (b), in any case, the original reciprocating motion (stroke motion) There were many difficulties and drawbacks in terms of performance.

In other words, in the conventional system, the moving force transmission mechanism is a series of elongated strips made of the same material, such as wire or steel strips, over the length range of the piston and the driven body, and also The moving force is transmitted to the driven body while applying tension to the long strip, and especially in the early stage of movement when the driven body is moved from a stopped state, a strong force is applied to the wire or steel strip. Tensile stress will act. As described above, elongation over time due to the repeated action of tensile stress during stroke motion and environmental conditions, especially thermal expansion due to changes in humidity, have a large influence, and furthermore, the movement path of the long strip becomes a curved path, and the loss of transmission force due to the friction between the path component and the band-shaped body is compounded, and the movement performance of the driven object, such as stroke and speed, cannot be maintained stably over a long period of time. Also, the durability of the seal structure between the force transmission mechanism (elongated strip) and the cylinder was lacking. In addition, various attempts have been made to maintain performance by minimizing the influence of thermal expansion, but these have had the disadvantage that the overall cost is extremely high due to the complexity of the structure. In addition, the performance problems mentioned above become more pronounced as the stroke becomes larger and the weight of the driven object (load) becomes larger. Therefore, the scope of application of this type of actuator is Naturally, there was a limit.

In view of these circumstances, the present invention is an actuator for reciprocating motion using a fluid pressure cylinder, which can maintain the original motion performance reliably, precisely, and stably over a long period of time, and which can be configured entirely with a coil surface. The purpose is to provide the following.

<Means for Solving the Problems> In order to achieve the above object, the actuator for reciprocating motion using fluid pressure according to the present invention is as described in detail at the beginning. A bending path 5 is formed across the side surface of the driven body 3 in the reciprocating direction, and a plurality of spheres 6 having the same diameter are placed in this bending path 5 with the peripheral surfaces of adjacent ones in contact with each other. By arranging the piston 2 in a rolling restricted state, a moving force transmission mechanism 4 for transmitting the reciprocating force of the piston 2 to the driven body 3 is configured, and the driven body 3 is provided with The structure includes a built-in mechanism 15 that can freely adjust the position of the moving force abutting surface 3A with respect to the group of spheres 6 along the axial direction of the path 5 within a range corresponding to the diameter D of at least one sphere 6. It has characteristics.

<Operation> According to the reciprocating actuator using a fluid pressure cylinder according to the present invention having such a characteristic configuration, the reciprocating driving force of the piston 2 due to the fluid pressure is closely arranged in the bending path 5. The force is transmitted to the driven body 3 through the pressing force based on the law of conservation of mechanical kinetic energy of the 6 groups of spheres, and even though it is a curved path 5, there is almost no escape of force at the curved portion. The loss of transmission force is extremely small. Therefore, the 6 groups of spheres that are the force transmission medium can be precisely machined and have a very small thermoelastic coefficient, so that the force transmission between the piston 2 and the driven body 3 is not affected by temperature changes. The degree of influence can be suppressed to an extremely small level. In addition, even if some manufacturing error occurs in the configuration of the bending path 5, which is a force transmission path, the moving force abutting surface 3A can be adjusted via the adjustment mechanism 15 built into the driven body 3. By adjusting the position, errors can be absorbed and the state of contact between the circumferential surfaces of each of the six groups of spheres can be reliably and easily brought out.

<Examples> Examples of the present invention will be described below based on the drawings.

In FIGS. 1 to 3, reference numeral 1 indicates plug heads 9A and 9 having passages 8A and 8B for supplying and discharging fluid pressure such as air and hydraulic pressure at both ends in the axial direction.
B is a cylinder fitted in an airtight or watertight state via a long vault 16A and a nut 16B, and 2 is a piston fitted and held in the cylinder 1 so as to be able to reciprocate and slide in the axial direction thereof. The piston 2 is configured to be movable reciprocatingly in the cylinder axis direction by controlling fluid pressure supply to the cylinder chambers 1A, 1B on both sides of the piston 2 via valves (not shown) and the flow paths 8A, 8B. 3 is the cylinder 1
Both the plug heads 9
The driven body is supported so as to be able to reciprocate in parallel or almost parallel to the cylinder axis direction along a fixedly connected shaft-shaped guide rail 10 between the upper ends of the cylinders A and 9B. It is configured to be able to attach one end of a link mechanism for opening/closing the automatic opening/closing door, a welding device, etc., and includes cylindrical portions 11, 11 that fit into the guide rail 10, and a moving force receiving member 12, which will be described later. ing. 5, 5 has knock pins 17 on both the plug heads 9A, 9B,
A member 5 having a semicircular shape in side view and fixedly connected via 17
a, 5b and semicircular curved members 5a', 5b' fixedly supported along the outside thereof, and semicircular curved path portions 5A, 5B formed at a position directly above the cylinder 1. Equally spaced circumferentially (center angle)
The two plug heads 9A, 9 are inserted through the moving force receiving member 12 at three locations separated by 120 degrees.
The upper straight path portions 5D, 5D are composed of three guide rods 7D fixedly installed in parallel to the cylinder axis between the cylinders 1 and 5D, and the upper straight path portions 5D, 5D are arranged at equal intervals on a circumference smaller than the inner diameter of the cylinder 1. 120 at center angle
A lower straight path portion consisting of three guide rods 7C that are fixedly installed parallel to the cylinder axis between the opposite surfaces of the plug heads 9A and 9B, with the piston 2 passing through them at three locations separated by a 5C, 5C are curved paths formed across both side surfaces of the piston 2 in the reciprocating direction and both side surfaces of the driven body 3, and in these curved paths 5, 5, steel is formed, respectively. Balls or molded balls made of nylon 66, which has excellent hardness and wear resistance, are used. A plurality of balls 6 and groups of 6 with the same diameter are placed in close contact with the peripheral surfaces of adjacent balls and their rolling is restricted. By arranging them in this manner, a moving force transmitting mechanism 4, 4 is constructed which transmits the reciprocating force of the piston 2 to the driven body 3 as a pressing force by a rigid body.
15 is the moving force receiving member 1 in the driven body 3
2, the members 15A, 15A have movable force abutting surfaces 3A, 3A for the six groups of spheres arranged in both the bending paths 5, 5, respectively.
is slidably fitted and held in the hole 12A provided through the moving force receiving member 12, and the opposing ends of these sliding members 15A, 15A are respectively inclined with respect to their sliding direction and are mutually held. cam surfaces 15a, 15a with opposite slopes are formed on both cam surfaces 15a, 15a.
A wedge member 15B having tapered surfaces 15b, 15b acting simultaneously on the sliding member 15a is configured to be movable in and out in a direction perpendicular to the sliding direction of the sliding members 15A, 15A via a screw member 5C. By moving the wedge member 15B in and out through the screw member 5C, the positions of the moving force abutting surfaces 3A, 3A of the sliding members 15A, 15A are changed along the axial direction of the bending paths 5, 5. Therefore, it is configured to be adjustable within a range corresponding to the diameter D of one sphere 6. In the figure, reference numerals 13 and 13 designate air-tight or oil-tight elastic seal members which are fitted in a cylindrical shape at the starting end portions of the through passages which penetrate the plug heads 9A and 9B among the bending passages 5 and 5, respectively.

In the actuator configured as described above, the piston 2 is reciprocated in the direction of the arrow The driving force is transmitted to the driven body 3 via the spheres 6 and groups of 6, and the driven body 3 is reciprocated in the direction of the arrow Y-Y' along a fixed path, which in turn moves movable members such as opening and closing doors. It is used to move back and forth between positions.

Next, another example will be listed.

[] In the embodiment shown in FIGS. 4 and 5, two cylinders 1, 1 each having a piston 2 fitted therein are arranged parallel to each other in the same plane, and the opposite sides of each piston 2, 2 are arranged side by side in the same plane. By forming bending paths 5, 5 separately over the side surface in the movement direction and both side surfaces of the driven body 3, and arranging the spheres 6, 6 groups closely in these bending paths 5, 5, the movement of the driven body 3 is It is constructed so that reciprocating motion can be performed by mutually different single-acting cylinders 1, 1.

[] The maximum adjustment range by the adjustment mechanism 15 may be the total diameter of the plurality of spheres 6.

<Effects of the invention> As can be understood from the detailed explanation above, when the present invention is used, (1) the mechanism for transmitting the reciprocating force of the piston to the driven body can be precisely machined, and the transmission efficiency is high. In addition to being of good quality, it does not undergo strain or deformation such as elongation, or exhibits very little deformation, regardless of the sliding torque of the driven body, the magnitude of the load, or even though it is subjected to repeated stress, and is also extremely resistant to thermal effects. Since the amount is small, it is possible to reliably and stably maintain the desired exercise performance over a long period of time.

(2) The seal structure between the force transmission mechanism and the cylinder is simple, and the durability of the seal can be improved.

(3) Since the stroke can be made larger and the load weight can be increased, the range of application can be expanded.

(4) Compared to conventional ones, it does not require any special mechanism or structure to suppress thermal expansion or mechanical distortion, and the sphere 6 can be obtained at low cost through mass production. Overall cost can be reduced.

(5) Furthermore, even if there is some manufacturing error in configuring the bending path, it is possible to reliably and easily bring out the state of contact between the peripheral surfaces of each group of six spheres. Performance can be ensured.

We were able to expect significant effects such as:

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of one embodiment, Fig. 2 is a partially cutaway plan view, Fig. 3 is an enlarged longitudinal sectional front view along the line of Fig. 1, and Figs. 4 and 5 are another embodiment. FIG. 4 is a schematic cross-sectional view and a longitudinal sectional front view taken along the line 4--, and FIG. 6 is a schematic longitudinal sectional side view showing a conventional example. 1 is the cylinder, 2 is the piston, 3 is the driven body, 4
is a moving force transmission mechanism, 5 is a bending path, 6 is a sphere, 7
C and 7C are guide rods, and 15 is an adjustment mechanism.

Claims (1)

[Claims for Utility Model Registration] A piston 2 fitted in a cylinder 1 is configured to be movable reciprocally in the cylinder axial direction by controlling the supply of fluid pressure to cylinder chambers 1A and 1B on both sides of the piston 2. At the same time,
A driven body 3 is provided on the outside of the cylinder 1 and is capable of reciprocating along a constant path parallel or substantially parallel to the cylinder axis direction, and the side surface of the driven body 3 in the reciprocating direction and the piston 2 in the reciprocating direction A curved path 5 is formed between the curved surface and the side surface, and a plurality of spheres 6 having the same diameter are placed in this curved path 5 in a state in which the peripheral surfaces of adjacent spheres are in contact with each other and in a state where rolling is restricted. By arranging the piston 2, the reciprocating driving force of the piston 2 is transferred to the driven body 3.
This is an actuator for reciprocating motion using a fluid pressure cylinder, in which a moving force transmission mechanism 4 is configured, and a moving force contact receiving surface 3A of the driven body 3 with respect to the group of spheres 6 is provided in the driven body 3. At least one position along the axial direction of the path 5
An actuator for reciprocating motion using a fluid pressure cylinder, characterized in that a mechanism 15 that can be freely adjusted in a range corresponding to the diameter D of two spheres 6 is incorporated. The mobile force transmission mechanism 4 is provided between both side surfaces of the single piston 2 and both side surfaces of the driven body 3. Actuator for reciprocating motion. Of the bent path 5, a straight path portion 5C located inside the cylinder 1 and a straight path portion 5D outside the cylinder 1 are connected to the piston 2 and the driven body 3.
Utilization of a fluid pressure cylinder according to claim 1, which is constituted by three or more guide rods 7C and 7D for moving spheres in the circumferential direction, which are fixedly installed in parallel with the cylinder axis through the cylinder axis. Actuator for reciprocating motion. A reciprocating actuator using a fluid pressure cylinder according to claim 1, wherein the six groups of spheres are steel balls. A reciprocating actuator using a fluid pressure cylinder according to claim 1, wherein the six groups of spheres are molded spheres made of nylon 66 with excellent hardness and wear resistance.