JPH0221039A - Electromagnetic brake - Google Patents

Abstract

PURPOSE:To extremely smoothly control a driver and stop it in the middle position, by providing a driven shaft which is turned and displaced in connection with displacement of the driver, and electromagnetic type disc brakes for providing controlling force to turning displacement of this shaft. CONSTITUTION:A driven shaft 103 is turned and displaced in connection with displacement of a driver. Electromagnetic disc brakes 1041 are set in two pairs; one 104a of the pairs is an exciting operation type, while the other is a non- exciting operation type. Pulse voltage may be repeatedly impressed on the electromagnetic disc brake means 1041 if needed. The driver is thus capable of being extremely smoothly braked, and also being stopped with accuracy in the middle position of its passage.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to an electromagnetic braking device.

[Conventional technology]

FIG. 10 is a schematic diagram illustrating a fluid pressure cylinder device equipped with a disc brake and an encoder. The cylinder device is installed in the center position of 02 so as to be freely rotatable, and is screwed to the piston 101 via a ball screw 103a. . Reference numeral 104 denotes an electromagnetic disc brake, which includes a brake disc 105 fixed to the driven shaft 103 and an electromagnetic coil device 106 that applies a continuous constant voltage to the brake disc 105 to apply braking force. Consisting of Note that fluid pressure is supplied to each cylinder chamber R, L via an appropriate meter-out circuit.

In the above device, the piston 101 is slidably displaced toward the R side or the R side of the cylinder chamber by the pressing force of the fluid pressure selectively supplied to the cylinder chamber R or L. In order to stop the piston 101 during the sliding displacement at an intermediate position, a constant voltage is continuously applied to the electromagnetic disc brake 104 via an appropriate control device.

As a result, the braking force of the electromagnetic disc brake 104 is applied to the driven shaft 103 to stop its rotation, and the piston 101 is also stopped in the same way.

[Problem to be solved by the invention]

Since the braking mechanism in the above device applies a continuous constant voltage to the electromagnetic disc brake 104, it can only apply braking force in a fixed manner to the piston 101 and the driven shaft 103. The braking force may be too large or too low depending on the high or low pressure state of the fluid pressure supplied to R or L, the speed of the piston 101, or the large or low load state. It is difficult to stop the piston lot smoothly and accurately during sliding displacement (at an intermediate position in the middle).Especially when the fluid is air and the movement range of the piston is large, it is difficult to stop the piston lot on the exhaust side and Since the compressibility of the air in the cylinder chamber is large (in the figure, the exhaust pressure P2 of the cylinder chamber R has a larger change in the amount of compression when the cylinder is stopped, compared to the pressurization P1 of the cylinder chamber in the figure), and this tendency This problem becomes more serious as the volume of the cylinder chamber R gradually increases or as the piston speed increases.

The present invention aims to solve the above problems,
That is, it is an object of the present invention to provide an electromagnetic braking device that can smoothly and accurately stop the driving body (piston) at an intermediate position even when the moving range of the driving body (piston) is large.

[Means to solve the problem]

That is, the present invention comprises a driven wheel that rotationally displaces in conjunction with the displacement of the driving body, and an electromagnetic disc brake means that applies a braking force to the rotational displacement of the shaft, and the electromagnetic disc brake means is optional. It is characterized in that a pulse voltage is repeatedly applied at a proper time.

[Effect]

By repeatedly applying an arbitrary pulse voltage to the electromagnetic disc brake means in a timely and repeated manner, the braking force of the electromagnetic disc brake means can be slightly changed as needed. It is possible to obtain the optimum braking force depending on the situation, etc., and also to achieve the unique smooth braking.

〔Example〕

Hereinafter, specific embodiments of the present invention will be described based on the drawings.

In the drawings, parts that are substantially the same as those of the conventional example are designated by the same reference numerals.

FIG. 1 shows a part of a fluid pressure cylinder device implementing a braking device according to the present invention, including a cylinder 102, a driven shaft 103,
It consists of an electromagnetic disc brake 1041, a pulse encoder 1, etc.

The driven shaft 103 is fitted inside the bearing 2 fixed to the cylinder 102, and the bearing 2 is held from both sides by the collar part 103b and the nut 3 screwed into the threaded part 103C, so that it can only rotate freely. ing.

The electromagnetic disc brakes 1041 are arranged in two sets;
Moreover, one type 1043 is an excitation type, and the other type 104b is a non-excitation type. Here, the excitation type refers to a type in which a voltage is applied to generate a braking force on a braked object, and the non-excitation type refers to a type in which a voltage is applied to generate a braking force on a braked object. This refers to the form in which the term is canceled. Both of them 104a and 104b are composed of a disk 4.5 integrally fixed to the driven shaft 103 and an electromagnetic coil device 6.7 facing the disk, and are specifically constructed as follows. That is, the - two disks 4
is fixed directly to the driven shaft 103 with a bolt 8 and key 9, and the other disk 5 is fixed with a bolt 11 to the other disk 4 via an elastic plate 10. Also, one electromagnetic coil device 7 is configured to apply voltage. Applied to disk 5
On the other hand, the other electromagnetic coil device 6 is energized to attract the friction disk 12 against the pressing force of a spring (not shown) and the voltage is applied to the other electromagnetic coil device 6. Friction disc 1 when no voltage is applied
2 is brought into pressure contact with the disc 4 by the pressing force of the spring to generate a constant braking force.

13 is an intermediate plate fixing the bearing 2, and the cylinder 1
02 and supports one of the electromagnetic coil devices 6 described above. Further, 14 is a brake casing bolted to the intermediate plate 13, and its end surface 14a is
supports the other electromagnetic coil device 7 described above.

The pulse encoder 1 is for detecting the rotational displacement of the driven shaft 103, and its input shaft 1a is connected to the driven shaft 10.
3 through a bending joint 15, and the main body is bolted to the outside of the end surface of the brake casing 14.

16 is a cover 17 surrounding the pulse encoder 1 is a spacer, and 18 is an end screw portion 103d of the driven shaft 103.
The axial displacement of the spacers 17 and 17 is regulated by the NAND threaded onto the spacers 17 and 17.

Although not shown, each of the electromagnetic disks and
A configuration is provided in which a pulse voltage of an arbitrary waveform or a continuous constant voltage can be applied independently to the brakes 104a and 104b at any time. This configuration can be realized by using a known pulse voltage generator.

Even in the above-mentioned apparatus, the fact that the driven shaft 103 is rotationally displaced in any direction in conjunction with the displacement of the driving body which is forcibly displaced by appropriate power is the same as in the conventional apparatus.

Next, an example of use of the above-mentioned braking device will be explained based on FIGS. 2 to 9.

a: When the driving body is displaced at high speed (in other words, the driven shaft 1
03 rotates at high speed) Figure 2 shows an example of the use of driven shaft 1.
03 is a diagram showing the relationship between the rotation speed and time, and
5 to 5 are diagrams showing the relationship between the pulse voltage waveform and the correspondingly generated brake torque.

At time t1, a pulse voltage whose waveform changes over time as shown in FIG. 3(a) is applied to the electromagnetic disc brake 104a. The figure shows a pulse wave in which the voltage is constant and the pulse width gradually increases. Note that pl is, for example, 10m5ec, and p2 is, for example, 3Qms e
c, etc. Then, the brake 104
At point a, a brake torque that changes as shown in FIG. 4B is generated, and the driven wheel, which was rotating at nl, gently reduces its rotation speed and reaches n2 at time L2, and is in an equilibrium state.

Then, at time t3, a pulse voltage having a constant waveform as shown by Wl in FIG. 4(a) is applied to the other electromagnetic disc brake 104b, to which a constant constant voltage had been applied until then. Then, the brake 104b is
), a brake torque that changes as T1 is generated, and as a result, the driven shaft 103 that was rotating at n2
The rotation speed is reduced to the rotation speed of the motor i, and at time t4, the rotation speed reaches a low rotation speed of n3, and an equilibrium state is reached.

Furthermore, at time t5, the same potential type disc brake 104
The pulse voltage applied to b disappears as shown by w2 in the same figure (a). Then, the brake 104b will generate a continuous braking torque as shown at T2 in FIG. Make sure it stops.

In this usage example, instead of applying a pulse voltage as shown in (a) in Figure 3, a pulse voltage whose voltage changes over time as shown in (a) in Figure 5 is applied. It may be applied. Even in this case, the electromagnetic disc brake 104a generates a brake torque as shown in FIG.

As can be understood from the above, even if the driving body is displaced at high speed, the rotation of the driven shaft 103 is changed as shown in FIG. 2, so the driving body is smoothly braked. Furthermore, since the rotation of the driven shaft 103 is stopped after the driven shaft 103 is set to a low rotational speed, it is possible to accurately stop the driving body at an intermediate position.

b: Example of use when the driving body is displaced at a relatively low speed (1)
Part 1 FIG. 6 is a diagram showing the relationship between the rotation speed of the driven shaft 103 and time, and FIG. 7 is a diagram showing the voltage waveform.

In FIG. 6, at time t1, the electromagnetic disc brake 104
A pulse voltage whose waveform changes over time as shown in FIG. 3(a) or FIG. 5(a) is applied to a. Then, as described above, the driven shaft 103, which had been rotating at a relatively low rotation speed n4, gently reduces its rotation speed, and reaches a low rotation speed n5 at time t7, resulting in an equilibrium state.

Then, at time t8, the electromagnetic disc brake 104b
The m-continuous constant voltage that had been applied until then disappears as shown in FIG. Then, the driven shaft 103 that was rotating at time n5 quickly reduces its rotational speed and stops reliably at time t9.

(2) Part 2 FIG. 8 is a diagram showing the relationship between the rotation speed of the driven shaft 103 and time, and FIG. 9 is a diagram showing the waveform of the pulse voltage.

In FIG. 8, at time t1, the electromagnetic disc brake 104
A pulse voltage whose waveform changes with time as shown by w3 and W4 in FIG. 9(a) or FIG. 9(b) is applied to b. Here, W3 is a wave with a constant pulse width and a gradually increasing voltage, and W4 is a wave with a constant voltage and a gradually increasing pulse width. Then, the driven shaft 103, which was rotating at n4, receives the brake torque that gradually increases, and gently reduces its rotational speed, reaching a low rotational speed of 06 at time tlO, and is in an equilibrium state.

Then, at time tll, the same potential type disc brake 10
The pulse voltage applied to 4b is made to disappear as shown in FIG. 9(a) or FIG. 9(b).

As a result, the driven shaft 103 that was rotating at time n6 quickly reduces its rotational speed and stops reliably at time t12. In this embodiment, the electromagnetic brake 104a is not used.

(3) Part 3 The plurality of electromagnetic disc brakes in each embodiment are as follows:
Each type has a different braking capacity depending on the application, and can be operated singly or in combination as required.

The relationship between the driving body and the driven shaft in the above embodiment is as follows.
As described in the figure, even if the linear displacement of the driving body is converted into the rotational displacement of the driven shaft 103 by a screw mechanism or the like, or the displacement such as rotation or revolution of the driving body is converted to the rotational displacement of the driven shaft 103 by an appropriate mechanism. It may also be a device that converts the rotational displacement into a rotational displacement.

Furthermore, the driving body and the driven wheel are constructed to be detachable through joints, and a control device (not shown) is used to control the pulse width and/or pulse voltage of the pulse voltage. A position stop device can also be obtained.

〔Effect of the invention〕

According to the present invention as described above, even when the driving body has a wide range of high and low speed changes, for example, the driving body can be braked extremely smoothly by selectively operating a plurality of brakes or by applying a braking action using a pulse voltage. This makes it possible to accurately stop the driving body at an intermediate position.

[Brief explanation of the drawing]

Figure 1 is a sectional view of a braking device that is an embodiment of the present invention, Figure 2 is a diagram showing the relationship between the rotation speed of the driven wheel and time, and Figures 3 to 5 are pulse voltage waveforms and their relationship. Figure 6 is a diagram showing the relationship between the rotation speed of the driven wheel and time, Figure 7 is a diagram showing the voltage waveform, and Figure 8 is a diagram showing the relationship between the driven wheel rotation speed and time. FIG. 9 is a diagram showing the waveform of the pulse voltage, and FIG. 10 is a conventional diagram. 103... Driven wheel 104a... Excitation operated electromagnetic disc brake 104b... Non-excitation operated electromagnetic disc brake

Claims (1)

[Scope of Claims] 1. Consisting of a driven shaft that rotationally displaces in conjunction with the displacement of the driving body, and an electromagnetic disc brake means that applies braking force to the rotational displacement of the shaft, the electromagnetic disc brake An electromagnetic braking device characterized in that the means is one in which an arbitrary pulse voltage is repeatedly applied in a timely manner. 2. The electromagnetic braking device according to claim 1, wherein two sets of the electromagnetic disc brake means are provided, and at least one of them is of a non-excitation type.