JPS60146909A - Rodless cylinder having positioner - Google Patents

Abstract

PURPOSE:To realize a small-sized, light weight rodless cylinder, by providing a nut main body on the piston having the main bodies of the cylinder which can freely extend/contract, on both sides, by mounting a screw shaft in the nut body, and by achieving detection of the amount of rotation and also braking of the screw shaft. CONSTITUTION:When a pressurized fluid is supplied to discharged from the chambers 2X, 2Y, of an an extension/contraction cylinders 2, and a piston 1, mount 15 and nut 8 are moved together, both extension/contraction cylinders 2 make extending/contracting operation in mutually reverse directions. Then, a screw shaft 4 rotates and a pulse encoder 5 detects the amount of said rotation and as a result, the amount of contraction of expansion of the cylinders 2 is detected. When the output signal of 8 pulse encoder reaches a specified value, a solenoid valve closes, at the same time, the moving piston 1 is accurately stopped and maintained at the specified position by actuation of a brake 6. The amount of contraction or expansion is detected in its state converted into rotational movement and enlarged. Thus positioning control with accurate detection of displacement and also with high accuracy can be carried out.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic or pneumatic hydraulic cylinder used to control the operation of various working devices such as welding equipment, and more specifically, to move the working device to any desired position within its operating stroke range. This invention relates to a cylinder with a positioning device that can be stopped at a location.

As a positioning device for this type of cylinder, the present applicants have developed a system in which a nut body is fixed to a piston attached to a cylinder body in a state in which the direction of the 70 axis is parallel to the direction of movement of the piston, and the nut body is screwed onto this nut body. The screw shaft is rotatably attached to the cylinder body and is installed in a sliding restricting manner, and a detector for detecting the amount of rotation of the screw shaft and a brake capable of applying a braking force to the screw shaft are provided. As a result, when the piston slides filJ k/1, the claw detects the amount of movement of the working device by the amount of rotation of the screw shaft, and applies the braking action necessary for stopping (positioning) the working device to the screw shaft. He developed a system that uses a brake on the shaft and has previously applied for a patent.

This earlier application utilizes a reverse boosting effect when the thrust force of the nut body that moves together with the piston is converted into the rotational force of the screw shaft, and the rotational force of the screw shaft is compared to the thrust force of the nut body. Therefore, it is possible to reduce the driving energy required for braking as much as possible while exhibiting a more effective braking effect than when applying braking force directly to the piston rod. In addition to the advantage of being able to capture the displacement of the stroke motion of the working device itself,
Since the displacement can be captured in an enlarged state by converting it into a rotational motion, there is an advantage that the displacement detection accuracy is very high and highly accurate positioning control can be performed.

However, in the prior application, the cylinder body has a fixed length, and the cylinder body extends outward from a piston fitted in the fixed length cylinder body while being pushed through the cylinder body. The working device is attached to the protruding end of the piston rod, or the working device mounting base is connected to the projecting end of the piston rod. As a result, the diameter of the cylinder body is also thicker by the same amount as the piston rod diameter (in addition, the presence of the rotation amount detector and brake that are installed to improve positioning control accuracy as described above tends to make the entire cylinder larger and heavier). There was a problem.

The present invention has an object to improve the problems of the prior application as described above.

In order to achieve the above object, the rodless cylinder with a positioning device according to the present invention has
A cylinder body is attached to the piston, and a nut body is attached to the piston so that its axial direction is parallel to the piston movement direction. The screw shaft screwed into the nut body is rotatable with respect to both telescopic cylinder bodies and installed in a sliding restricted state, and the amount of rotation of the screw shaft is detected. It has a characteristic configuration in that the detector and the screw shaft are provided with a brake that can apply a braking force, and the following effects have been achieved.

By making the cylinder body telescopic and allowing it to expand and contract together with the piston, the working device attached to the piston can be stroked over the maximum expansion and contraction range of one cylinder body. In order to obtain the same stroke and the same moving speed as that of the earlier application, it is possible to shorten the space equivalent to the fixed length cylinder body of the earlier application in the stroke movement direction, and to reduce the cylinder diameter by omitting the piston rod. Since it can be made extremely small, as mentioned above, even though it is equipped with a rotation amount detector and a brake to perform positioning with extremely high precision, the whole thing can be made small @ Quantity, and therefore it is highly versatile and easy to use. This made it possible to perform positioning with extremely high precision.

Embodiments of the present invention will be described below with reference to the drawings.

In Figures 1 and 2, (1) is a piston, and (
(!l is a plurality of pieces with successively smaller diameters (4 on the mouth surface)
Although shown in a book, the number may be eight or six or more. ) cylindrical cylinder member (gA) , (gB) ,
ω0), (gD), QS, 0RB), (8S, (2D) are fitted concentrically to form a telescopically telescopic cylinder body. The piston (2Δ) is connected to the piston (
The minimum diameter cylindrical cylinder member (Jl(D), (2D) of both telescopic cylinder bodies (RII(t)) is fixed to both sides in the direction of movement of the cylinder member (Jl(D), (2D)). 9m), ΦB) are formed, and thus the left and right chambers (,Zx), (
BY) With the stroke movement of the piston (1) by supplying and discharging pressure fluid to and from It is configured to extend and contract in a contradictory manner across the body. (711 (7) is the both telescopic cylinder bodies (
2) Minimum diameter cylindrical cylinder member (i) of (t),
There is a pair of mounts that fixedly support each tip of the telescopic cylinder body (21, (11), and between the pair of mounts (7), (7) The slide kite shaft f81 h (sl) is bridge-fixed, and the working device mounting base e@ is provided in a state where it can move integrally with the piston (1) in a state where it is fitted to the guide shaft (a) r (81). That's it.

When configuring the positioning device in such a hydraulic rodless cylinder, both telescopic cylinder bodies (2),
(2) a stroke movement of said piston (1);
The pick is equipped with a sliding rotation conversion mechanism a0 (details will be described later) using a ball screw to convert the telescopic movement of the cylinder body (r (e) into rotational movement), and this mechanism θ
・The screw shaft (4) which is a component of the head cover (II)
The holes (11) formed in the
An example of an electromagnetic brake (6) that can apply a button braking force to the screw shaft (4) on the protruding shaft portion side of the screw shaft (4), and a detector that detects the amount of rotation of the screw shaft (4). A total of 61 pulse encoders are installed.

The sliding rotation converter 1i01 has a helical shaft portion (
The screw shaft (4) consisting of the output shaft part (4,) and the output shaft part (4b) is installed in a sliding restricted state, that is, only freely rotated, through a needle bearing ano and a tapered roller bearing foot. 1), at the rear thereof, a large number of balls are located coaxially with the sliding wheel core of the piston (1) and are movable along the helical groove (40) formed in the helical shaft portion (4a). The nut body (3) is screwed and fixed.

The group of balls 04 is configured to circulate within the nut body (8). The members in the figure are filled with sealing material, and the telescopic cylinder body (both chambers i* of 211(t)) O,
(Piston 0 due to pressure fluid supply control for 2!η
), the mounting base 050, and the nut body (8) are moved together, both the telescopic cylinder bodies (2) # (2+ are telescopically operated and the screw shaft (4) rotates, and the amount of rotation is Pulse encoder (S) #f Detection f.
Displacement amount of piston (1), cylinder body (2).

(There is a l-to-l correspondence between the amount of expansion and contraction and the amount of rotation detected, and the pulse x that becomes the amount of rotation by greatly amplifying the amount of displacement and the amount of expansion and contraction) 11 (pulses) are counted by the controller, and when this matches the set value, the control signal of the controller closes the electromagnetic valve in the pressure fluid circuit, and at the same time activates the electromagnetic brake (6) to stop the piston from zero. ) will be reliably stopped and maintained in position.

In the rodless cylinder with a positioning device having the above-mentioned configuration, various working devices are mounted and fixed on the end of the mounting base on which the piston (+) moves together, as shown in Fig. 4. This makes it possible to stroke the working device over a desired range and position it reliably and accurately at the end of the stroke.

Figures 5 and 6 show two long and short rodless cylinders according to the present invention. An example will be shown in which rail-type stroke guides are used for both the X-axis and the Y-axis.

Next, another example will be listed. (None of these are shown) (1) The brake (6) may be a hydraulic brake, a band brake, a drum brake, a power generation brake, or the like other than an electromagnetic brake.

[13 The rotation amount detector (5) may be a mechanical output type sensor other than a pulse encoder.

[Engineer] The pressure fluid may be any one of hydraulic pressure, water pressure, pneumatic pressure, etc.

] The slide guide shaft (8) may not be provided.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway side view, Figure 2 is a plan view of the flR location,
Figure 8 is Figure 1! -! 4 is a schematic side view of the device in use, and FIGS. 5 and 6 are a schematic plan view and side view showing other conditions of use. (!)...Piston, (2...Telescopic cylinder body, (8)...Nut body, (4+...
...screw shaft, (5) ...rotation amount detector, (6
)······brake.

Claims (1)

[Claims] ■ This piston (
1) Cylinder body +21 that is oppositely expandable and contractible over the same or almost the same range along the direction of movement.
, (21 is attached, and the nut body (21 is attached to the piston 0)
8) is fixed with its axial direction parallel to the movement direction of the piston (1), and the threaded shaft (4) that is screwed into this nut body (8) is connected to both the telescopic cylinder bodies (21, (2). ) is rotatably mounted in a sliding restricted state, and a detector (4) for detecting the amount of rotation of the screw shaft (4)
6) and a rodless cylinder with a positioning device, which is provided with a brake (6) capable of applying a braking force to the screw shaft (4). (2) The rodless cylinder with a positioning device according to claim 0, wherein the combination of the nut body (s) and the screw shaft (4) is a ball screw. (2) The rodless cylinder with a positioning device according to claim 0, wherein the detector (5) is a pulse encoder.