JPS6338435Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to the invention of a VTR cylinder lead surface measuring device, and aims to obtain a mechanism that can stably and accurately measure the accuracy of the lead surface in the cylinder of a VTR (video tape recorder). It is something.

Industrial applications Measurement of VTR cylinder lead surface.

2. Description of the Related Art Representative examples of conventionally known cylinder mechanisms for VTRs are shown in FIGS. 4 and 5. That is, it consists of an upper cylinder 1 and a lower cylinder 2, and the lower cylinder 2 has a fifth cylinder partially enlarged.
As shown in the figure, a lead surface 2a on which the tape runs is formed. However, such a VTR
Obtaining appropriate linearity of the lead surface 2a of the cylinder mechanism is extremely important in obtaining the desired function of the mechanism, and for the purpose of measuring the lead surface 2a, a mechanism as shown in FIG. 6 has been conventionally known. It is being

That is, in the one shown in FIG. 6, a support 5 for positioning the lower cylinder 2 as described above is provided on one side of the machine base 20, and a handle 3 is used on the other side to adjust the longitudinal position of the holding seat 4b. Adjustment stand 4
c is attached, and the tip of the threaded rod portion 4a of the other handle 4 engages with the holding seat 4b,
An engaging part body 26a installed in a lifting platform 26 having a stylus 10 is screwed into the threaded rod part 4a, and the handle 4
The lifting table 26 is raised and lowered by the rotation of the stylus 1.
0 comes into contact with the above-mentioned lead surface 2a, and the lifting platform 2
The linearity is measured in an amplifier connected to 6.

Problems that the invention aims to solve In the case of the conventional lead surface measurement mechanism as described above,
Since the linearity of the lead surface 2a described above is determined only by operating the handle, it is difficult to accurately measure the linearity of the lead surface 2a under conditions where high accuracy is required, such as 3 μm or less. That is, since the width d of the lead surface is very narrow, around 0.15 mm, it is necessary to operate with great care, and it is difficult to obtain accurate measurement results, especially when the stylus 10 is In many cases, the stylus 10 collides with the lower cylinder 2 and is damaged, and it is preferable for the stylus 10 to contact the vicinity immediately below the upper edge of the cylinder 2. However, in order to achieve this positioning with high precision, the screw rod part that rotates during adjustment operations is important. It is difficult to achieve stable positioning due to bumps and the like in the portion 14a. Of course, these results inevitably affect measurement accuracy.

Means for solving the problems The present invention was devised to solve the problems of the conventional ones as mentioned above.
In addition to positioning the lower cylinder of the VTR, an adjustment table is provided on the other side of the machine base so that the stylus body can be slid in the horizontal direction, so that it can be raised and lowered;
A distance sensor attached to the stylus body is mounted on the adjustment table so as to be able to slide together with the stylus body, a screw shaft driven by a motor is engaged with the distance sensor, and a power supply circuit for the motor is connected. The present invention proposes a VTR cylinder lead surface measuring device characterized in that a control circuit is provided which operates on and off in the forward or reverse direction depending on the deviation between a predetermined set value and a value detected by the distance sensor.

Effects In the device according to the present invention as described above, the distance sensor and the stylus are driven by a motor, and a control circuit that performs control operations based on the detected value by the distance sensor and a predetermined set value is incorporated in the power supply circuit for the motor. Therefore, it is clear that the motor is effectively rotated forward or reverse depending on the deviation from the set value, thereby enabling automatic positioning at an appropriate distance with respect to the lower cylinder.

Embodiment A specific embodiment of the present invention as shown in the attached drawings will be described. As shown in FIG. Although it is similar to that shown in FIG. 3, a support seat 9 is attached to the other side of the machine base 20, and a vertical screw rod 16 rotated by a motor 6 is rotatably supported. Further, the base end of the adjustment table 5, which is engaged with the guide pin 19 attached to the front end of the support seat 9, is screwed into the vertical screw 16, and is bored from the front end surface of the adjustment table 5. A stylus body 10a with a stylus 10 attached to the front end is accommodated in the guide hole 15, and a connecting portion 10b formed in the stylus body 10a is inserted through an opening 15a formed at the bottom of the guide hole 15. Protruding sensor body 1
It is attached to 1a. The sensor body 11a
has a distance sensor 11 at its tip and is slidably provided on a holding part 5b hanging down from the front end of the adjustment table 5, and a screw hole 18 is formed in the base end of the sensor body 11a. A screw rod 8 driven by the second motor 7 is screwed into the screw hole 18 . 21 are retaining pins, power cords are connected to the motors 6 and 7, respectively, and the stylus 1
The code from 0 is routed to an amplifier, while the code from distance sensor 11 is routed to a control circuit 17, such as the Wheatstone bridge circuit of FIG. 3, described below.

The control circuit 17 shown in FIG. 3 rotates the motor 7 forward or reverse depending on the deviation between the detected value by the distance sensor 11 and a predetermined set value as described above. As shown in the figure, a predetermined voltage is obtained depending on the distance l from the cylinder 2, and a Wheatstone bridge circuit is formed for the motor 7 by the distance sensor 11 and the variable resistor 14 that obtains a predetermined set value. However, other suitable control circuits 17 may be employed. Moreover, if the control circuit 17 is provided with a light emitting diode 12 as shown in FIG. 3, the set value by the variable resistor 14 and the distance sensor 1
The light is turned on when the detected value obtained in step 1 is not balanced, and the light is turned off when the target distance is set, so that the positioning state can be checked at a glance.

The relationship between the distance sensor 11 and the stylus 10 can be set on the same line as shown in FIG. All you have to do is shift l. Once the position has been automatically determined as described above, setting of the stylus 10 is completed by activating the motor 6 and lowering the stylus 10 onto the lead surface of the cylinder, and measurement can be performed using a known measuring circuit unit. It will be started.

(Effect of the invention) According to the invention as described above, the distance sensor 11 and the stylus 10 are driven by a motor by the control circuit 17 incorporating the distance sensor 11 to advance and retreat with respect to a workpiece such as a cylinder. As a result, the proper stylus position can be automatically and accurately obtained, which means that the operator does not need careful manual operation, and the measurement condition can be shortened without damaging either the stylus or the workpiece. It is a device that can be formed in a short amount of time and has great practical effects.

[Brief explanation of the drawing]

The drawings show the technical content of the present invention; Figure 1 is a longitudinal cross-sectional side view of the lead surface measuring device according to the present invention, and Figure 2 shows the voltage relationship depending on the distance between the distance sensor and the workpiece. Figure 3 is an explanatory diagram of one example of the control circuit in the present invention, Figure 4 is a side view of the VTR cylinder mechanism, Figure 5 is an enlarged sectional view of a part of it, and Figure 6 is the VTR cylinder. 1 is a cutaway side view of a conventional measuring device for a mechanism; FIG. In these drawings, 2 is the lower cylinder of the workpiece, 2a is the lead surface thereof, 5 is the adjustment table, 6 and 7 are the motors, 8 is the screw rod, 9 is the support seat, 1
0 is a stylus, 11 is a distance sensor, 14 is a variable resistor, 15 is a guide hole, 15a is an opening thereof, 16 is a vertical screw, 17 is a control circuit, and 20 is a machine base.

Claims (1)

[Scope of utility model registration request] The VTR lower cylinder is positioned on one side of the machine base, and an adjustment base on the other side of the machine base is provided with a stylus body that can be slid in the horizontal direction so that it can be moved up and down. A distance sensor attached to the stylus body is attached so that it can slide together with the stylus body, a screw shaft driven by a motor is engaged with the distance sensor, and a predetermined setting value is applied to the power supply circuit for the motor. A VTR cylinder lead surface measuring device, characterized in that it is provided with a control circuit that turns on and off in the forward or reverse direction depending on the deviation from the value detected by the distance sensor.