JPH0516187U - Angle detector - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an angle detector with a simple structure and high reliability even under high pressure water. A cam plate 4 is integrally provided on a rotating shaft 3 supported by a case 1, and a strain gauge 10 is attached to the root of a cantilever 5 whose rear end is fixed to the case 1 side.
The tip of the cantilever 5 is pressed against the cam surface of the cam plate 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an angle detector such as a drive actuator used under special fluid conditions in high pressure water.

[0002]

[Prior Art]

 A rack and pinion type swing actuator is shown in FIGS. 6 and 7 as an example of an actuator used under high-pressure water.

This actuator is mainly composed of a case 101, a rack piston 102 reciprocally housed therein, a pinion 103a that meshes with a rack 102a of the rack piston 102, and a pinion shaft 103 integrated with the pinion 103a. The rack piston 102 is constituted by a supporting bearing 108, an arm member 107 integrated with the pinion shaft 103, and the like, and a drive medium generated by a pump or the like is taken in and out from the covers 105a and 105b at both ends of the case 101. In this case, the pinion 103a and the pinion shaft 103 which are driven in the left-right direction and mesh with the rack 102a of the rack piston 102 are rotated, and thereby the rotational drive is transmitted to the arm member 107 integrated with the pinion shaft 103.

FIG. 8 shows an example of a manipulator 128 configured by combining three rocking type actuators 100 of this type. The manipulator 128 controls the rotation angles of the first shaft 129, the second shaft 130, and the third shaft 131 to grip and move the object 132, and various combinations of actuator mounting directions and arm lengths l. By changing the, it is possible to obtain various operating modes and operating ranges.

Here, each actuator 100 is equipped with an electric output potentiometer 123 as an angle detector for controlling the operating angle thereof at the end of the pinion shaft 103. The potentiometer 123 is attached to a mounting piece 120 that is normally extended from the case 101, which is the fixed side, and its rotating shaft 124 is connected to the pinion shaft 103.

By the way, when this kind of actuator is used underwater, as shown in FIG. 7, the potentiometer 123 which is an electric component is housed in the housing container 121 to protect it from external water. In addition, a seal member 126 such as an O-ring is attached to the penetrating portion of the rotary shaft 124 to prevent external water from entering the storage container 121. In FIG. 7, reference numeral 125 is a waterproof type electrical signal connector.

In addition, in applications such as submersibles that are used in seawater and where high water pressure acts, the insulating oil 127 is enclosed in the storage container 121 and the pressure of the insulating oil 127 is adjusted to the ambient high water pressure. A flexible bellows 122 is attached to the storage container 121 for the purpose of equalizing the same pressure as the above. This is aimed at reducing the pressure resistance of the storage container 121 and improving the sealing life of the shaft sealing material 126 by making the ambient water pressure and the pressure of the insulating oil 127 in the storage container 121 substantially the same.

[0008]

[Problems to be solved by the device]

 However, due to long-term use, the bellows part is damaged and the shaft seal material 126 is worn due to repeated expansion and contraction of the bellows 122 due to changes in ambient pressure and temperature changes. Due to the intrusion of water, the insulation of the potentiometer 123 becomes defective, and it becomes impossible to detect the actual operating angle of the actuator.

There is also a problem that the structure is complicated and the assembly is troublesome, such as the need to incorporate the potentiometer 123 into the storage container 121 and the sealing work of the insulating oil.

[0010]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, in the present invention, a cam plate is provided integrally with a portion of the rotating shaft supported by the case inside the case, the rear end of the cantilever is fixed to the case side, and a strain gauge is attached to the root part. On the other hand, the tip of the cantilever is pressed against the cam-shaped surface of the cam plate to form an angle detector.

[0011]

[Action]

 In the angle detector having the above-described configuration, when the cam plate rotates, the strain gauge detects the strain amount due to the cam displacement amount, and the rotation angle is obtained based on the strain amount.

[0012]

【Example】

 FIG. 1 shows the appearance of an angle detector according to an embodiment of the present invention, FIG. 2 shows its transverse section, and FIG. 3 shows its longitudinal section.

Reference numeral 1 denotes a case, and a rotating shaft 3 is supported by bearings 2 a and 2 b provided on a front wall 1 a and a rear wall 1 b of the case 1. The rotating shaft 3 is connected to a shaft to be detected such as an actuator shaft.

A cam plate 4 is integrally attached to the rotary shaft 3 in the case 1. As shown in FIG. 2, the cam plate 4 has a cam shape in which the displacement amount gradually increases in the circumferential direction, and the maximum displacement is δ.

In the case 1, a rear end of the cantilever 5 is fixed to a mount 6 provided on an upper wall 1c of the case 1 with a bolt 7 and a nut 8. A slider 9 is attached to the front end of the cantilever 5, and the slider 9 slidably contacts the outer surface (cam-shaped surface) of the cam plate 4. A strain gauge 10 is attached to the base of the cantilever 5. The surface of the strain gauge 10 is coated with a water resistant treatment.

A gauge wire 11 connected to the strain gauge 10 is guided to a terminal block 12 provided on the inner surface of the case 1 and connected to a take-out cable 13 at the terminal block 12, and the take-out cable 13 is an indicator outside the case 1. Have been led to. The surface of the terminal block 12 is also coated with water resistant treatment.

The case 1 itself does not have pressure resistance because the surrounding fluid such as water freely permeates through the holes 14 provided in the front wall 1a and the rear wall 1b to fill the inside with the fluid. Filters 15 are provided in the holes 14 provided in the front wall 1a and the rear wall 1b of the case 1 to prevent foreign matters floating around the case 1 from entering the case 1.

Next, the operation of the angle detector will be described with reference to FIG. 4 which is an example of an operating state and FIGS. 5A and 5B which are output detection diagrams.

When the rotary shaft 3 or the cam plate 4 rotates in the direction shown by the arrow in FIG. 2, the tip end of the cantilever 5 is pushed up along the cam shape via the slider 9, and is shown in FIG. As it causes a bend. Along with this, strain is generated in the strain gauge 10 attached to the root portion of the cantilever 5, and the strain amount ε according to the bending of the cantilever 5 is detected.

Therefore, the relationship between the rotation angle θ of the cam plate 4 and the outer diameter change amount δ of the cam plate outer peripheral surface is obtained as shown in FIG. 5A, and the outer diameter change amount δ and the strain gauge 10 are detected. By setting the strain amount ε as shown in FIG. 5B, the strain amount ε proportional to the rotation angle θ can be obtained. Therefore, by detecting the strain amount ε, the rotation angle of the rotary shaft 3 can be Can be measured.

When the outer peripheral surface of the cam plate 4 or the slider 9 is worn, the initial relationship between the rotation angle θ and the change amount δ is lost, so that the materials of the two should be slippery and hard to wear, or coated. And give it. Further, since the filter 15 prevents foreign matter from entering the case 1, it is possible to prevent foreign matter from being caught between the tip of the cantilever 5 and the cam plate 4 to cause a measurement amount error. .

In the above-described embodiment, the displacement is applied over substantially the entire circumferential surface of the cam plate 4, but the displacement is applied only partially (for example, half the circumference) in accordance with the angle range of measurement. Good. Furthermore, it is possible to change the measurement mode by providing a plurality of cam plates 4 at different positions.

[0023]

[Effect of the device]

 According to the angle detector of the present invention, the structure can be simplified as compared with the conventional potentiometer type. In addition, by applying water resistance treatment to the strain gauge part, even if external high-pressure water enters the case that houses the cantilever and strain gauge, there is no problem in detecting the rotation angle. However, it is not necessary to seal the case, and there is no need to worry about deterioration of reliability due to water infiltration due to deterioration of the seal part due to long-term use.

[Brief description of drawings]

FIG. 1 is an external view of an embodiment.

FIG. 2 is a cross-sectional view of one embodiment.

FIG. 3 is a vertical sectional view of one embodiment.

FIG. 4 is a sectional view of an angle detection state.

5A is a diagram showing a relationship between an angle and a displacement amount, and FIG. 5B is a diagram showing a relationship between a displacement amount and a fixed amount.

FIG. 6 is a vertical sectional view of an oscillating actuator.

7 is an explanatory view of a conventional angle detector shown in the cross section of FIG.

8 is an external view of a manipulator configured by connecting the actuators shown in FIGS. 6 and 7 in cascade.

[Explanation of symbols]

 1 Case 3 Rotation axis 4 Cam plate 5 Cantilever 10 Strain gauge

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tatsuo Katayama 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries Ltd. Kobe Shipyard

Claims (1)

[Scope of utility model registration request] 1. A cam plate is integrally provided on a portion of the rotating shaft supported by the case in the case, a rear end of the cantilever is fixed to the case side, and a strain gauge is attached to a root portion of the cantilever. An angle detector characterized in that a tip portion is pressed against a cam-shaped surface of the cam plate.