JPH0533005U - Dimension measuring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a device that can adapt to changes in a work piece and can ensure accuracy. [Structure] The detection member 1 is rotationally driven by a motor 2 and is driven forward by a value corresponding to the amount of rotation. The torque change when the detection member 1 hits the work is transmitted to the motor 2 via the spring 19, and the load of the motor 2 increases and the current increases. Therefore, this is detected by the current change detection device, and the current supply timing The current supply period detection device detects the current supply period from when the current reaches a predetermined value or more. Based on the motor rotation amount obtained from this current supply period, the amount of advancement of the detection member is obtained by the dimension measuring unit.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a size measuring device for measuring the size of an object to be measured.

[0002]

[Prior Art]

 In recent years, NC devices have become widespread, and workpieces can be processed with high dimensional accuracy by performing predetermined settings. However, it is difficult to maintain this accuracy for a long period of time due to tool wear and other causes. Therefore, after machining the workpiece, measure the dimensions with a measuring device, and if a defective product occurs, set the NC device at that point. Correcting.

As this measuring device, as shown in FIG. 5, a cylinder 100 is driven by hydraulic pressure or air to advance a detection unit 101, and a differential transformer type detector or an optical sensor detects the amount of movement of the detection unit. is there. However, in the case of using hydraulic pressure, the forward movement of the detection unit is stopped when the detection unit hits the work and a change in hydraulic pressure occurs, so it is necessary to change the hydraulic pressure to a certain degree or more. For this reason, the forward movement of the detection unit 101 cannot be stopped at a delicate timing, and the measurement accuracy is limited.

Further, since it is necessary to move the detection unit 101 forward to the full stroke, it is necessary to change the setting each time the work is changed, resulting in poor workability.

Therefore, as shown in FIG. 6, the rotation of the motor 102 is converted into a forward movement to move the detection unit 101 forward, and the amount of rotation of the motor until it abuts the work is investigated, and the detection unit 101 is detected from the rotation amount. There is also a proposal to detect the movement amount of the.

[0006]

[Problems to be solved by the device]

 However, such a device has a problem in that the pressure cannot be kept constant and accuracy cannot be ensured because the timing at which the detection part hits the work is visually determined. In addition, there is a problem that the impact when the detection unit hits the work is directly transmitted to the motor.

The present invention has been made in view of such a situation, and provides an apparatus which can be freely adapted to a change of a work and can ensure accuracy.

[0008]

[Means for Solving the Problems]

 In order to solve such a problem, the present invention provides a male screw coupled to a motor rotation shaft through a coupling portion that absorbs a force applied in the axial direction of a motor, and a male screw screwed to rotate the motor. To a linear motion and a detection member is provided at the tip of the sleeve, a current change detector that detects when the current supplied to the motor exceeds a specified value, and a current change from the time when the current is supplied. Is provided with a current supply period detection device that detects a current supply period until the state becomes a value equal to or more than the predetermined value, and a dimension measurement unit that obtains the amount of advance of the detection unit based on the motor rotation amount obtained from the current supply period. It is a thing.

[0009]

[Action]

 The detection member is rotationally driven by the motor and is driven forward by a value corresponding to the amount of rotation. The change in torque when the detection member hits the workpiece is transmitted to the motor through the coupling part, and the load on the motor increases and the current increases, so this is detected by the current change detection device, and from the time the current is supplied. The current supply period detection device detects the current supply period until the current reaches a predetermined value or more. Based on the motor rotation amount obtained from this current supply period, the amount of advancement of the detection member is obtained by the dimension measuring unit.

[0010]

【Example】

 FIG. 1 is a block diagram showing an embodiment of the present invention. The detection member 1 rotationally driven by the motor 2 advances the detection member 1 by a value corresponding to the amount of rotation of the motor 2, and measures the dimension of the object to be measured from the amount of advance. FIG. 2 is a view showing the operation of this device, FIG. 2 (a) shows a state before the detection member 1 advances, and FIG. 2 (b) shows the sleeve 7 advanced by the rotation / advance conversion device 6 and the detection member 1 Is being advanced.

When the detection member 1 is moved forward by the rotation drive and hits the work, the detection member 1 cannot move any further, so the detection member 1 stops the advancement. In this state, the detection member does not move forward even if the motor 2 rotates, so that the motor 2 becomes overloaded and the current flowing there increases. At this time, the current change detecting device 3 detects the current supplied to the current change detecting device 3 and detects a state in which the current value exceeds a predetermined value.

This signal is supplied to the current supply period detection device 4, and the current supply period from the time when the current is supplied until the current becomes equal to or more than the predetermined value is detected, and the value of the current supply period is measured by the dimension measuring unit 5 The amount of rotation of the motor is obtained from this, and the amount of advancement of the detection member 1 is obtained based on this.

FIG. 3 is a sectional view showing the details of the rotation / advancement device 6 for advancing the detection member 1. The left end of the rotary shaft 2a of the motor 2 and the right single end of the rotary shaft 12 are provided on the collar 15, respectively. In addition to being inserted into the hollow portion, the grooves 15a and 15b provided in the collar 15 are coupled by the pins 16a and 16b to rotate integrally. Since the rotary shafts 2a and 12 are arranged so that their ends do not come into contact with each other, the rotary shaft 12 can be moved slightly in the left-right direction.

Reference numerals 17 a and 17 b denote thrust bearings that are held by a bearing holder 18 and fixed to the shaft 12 by a double nut 19 that is screwed onto the right end of the rotary shaft 12, and that supports the rotary shaft 12. Reference numeral 19 is a spring that absorbs a force in the direction of the motor 2 transmitted through the rotary shaft 12, and is biased by a spring retainer 21 that is screwed into a screw cut on the inner wall of the case 20 and is on the right side of the bearing holder 18. A predetermined force is applied to the wall to the left in the figure.

The rotating shaft 12 has a male screw 12a continuously cut from a position near the left end to a predetermined position, and a female screw 7a cut at the right end of the sleeve 7 is screwed into the male screw 12a. A key 13 is embedded near the right end of the sleeve 7, and the key 13 is adapted to move forward and backward along a key groove 14 provided inside the case 20 of the rotation / advancement device 6. ..

The collar 15 and the spring 19 form a joint that absorbs the force applied in the axial direction of the motor 2.

In the device configured as described above, the rotation shaft 12 is rotated by the rotation of the motor 2. The sleeve 7 is screwed onto the rotary shaft 12, and the key 13 is embedded in the sleeve 7, and since the key 13 is inserted into the key groove 14, the sleeve 7 does not rotate. As a result, the sleeve 7 is advanced by applying a force in the forward direction to the female screw 7a screwed with the male screw 12a cut on the shaft 12.

When the detecting member 1 provided at the tip of the sleeve 7 hits the work, the detecting member 1 does not move forward any more, so that the motor 2 is overloaded and the current flowing through the motor 2 increases. Therefore, the motor rotation amount can be known by counting the pulses from the pulse encoder generated in response to the rotation of the motor from the time when the current is supplied to the time when the current exceeds a predetermined value, and the motor rotation amount can be detected. The amount of advance of the member 1 is known, and this calculation is performed by the dimension measuring unit 5. The measured dimensional data is output from the rear connector, but may be displayed on the main body.

When the detection member 1 hits the work, the sleeve 7 stops advancing, whereby a rightward force, that is, a force in the motor direction acts on the rotary shaft 12. However, since the rotary shaft 12 is inserted in the collar 15 so as to be movable in the left-right direction in the figure, the force acting in the motor direction moves the rotary shaft 12 in that direction, and the force is applied by the spring 19 to the force. Be absorbed. Since the rotating shaft of the motor 2 and the rotating shaft 12 are moved so as not to contact each other, the force from the rotating shaft 12 is not applied to the motor 2.

FIG. 4 is a perspective view showing another embodiment of the collar 15, which is structurally strong.

[0021]

[Effect of the device]

 As described above, the present invention detects a sudden change in the motor current when the motor overloads when the detection member hits the workpiece, and the amount of change is very large. It is possible to detect the timing to stop the measurement with high accuracy, which greatly reduces the deviation of the measured values and improves the measurement accuracy. Further, since the forward movement of the detection member is stopped when the detection member hits the work, there is an effect that it can be freely adapted even if the work is changed. Further, there is an effect that the impact when the detection member hits the work is not transmitted to the motor.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing the entire structure.

FIG. 3 is a sectional view showing an embodiment showing the internal structure of the rotation / forward conversion device.

FIG. 4 is a perspective view showing another embodiment of the collar.

FIG. 5 is a diagram showing a conventional example.

FIG. 6 is a diagram showing another conventional example.

[Explanation of symbols]

 1 Detection Member 2 Motor 3 Current Change Detection Device 4 Current Supply Period Detection Device 5 Dimension Measuring Unit 6 Rotation / Forward Conversion Device 7 Sleeve 7 12 Rotating Shaft 13 Key 14 Key Groove 15 Color 16 Pin 17 Bearing 18 Bearing Restoration 20 Case

Claims (1)

[Scope of utility model registration request] 1. A male screw coupled to a motor rotation shaft via a coupling portion that absorbs a force applied in the axial direction of the motor, and a male screw screwed to the male screw to convert the rotation of the motor into a rectilinear motion and to tip the tip. A sleeve provided with a detection member, a current change detection device for detecting a state in which the current supplied to the motor exceeds a predetermined value, and from the time when the current is supplied until the current reaches the above-specified value The current supply period detection device for detecting the current supply period, and the dimension measurement device configured to obtain the amount of forward movement of the detection unit based on the motor rotation amount obtained from the current supply period.