JPH03286414A - Vtr shaft inserting method - Google Patents

Abstract

PURPOSE:To highly precisely insert a drum shaft, and to make the correction working of a lower drum unnecessary, and to make a shaft press fitting device unnecessary by inserting quickly an upper drum shaft cooled below -20 deg.C into a lower drum hole heated at about 80 deg.C. CONSTITUTION:The upper drum shaft 5 is worked beforehand so that it turns into the relation of tight fit to a lower drum hole 1a at room temperature, and the lower drum 1 is heated and kept at about 80 deg.C, and the upper drum shaft 5 is cooled below -20 deg.C. Then, the upper drum shaft 5 cooled below -20 deg.C is inserted quickly into the lower drum hole 1a heated at about 80 deg.C while the relation of loose fit is kept between them. Accordingly, since the lower drum is kept at about 80 deg.C, the inner diameter of its lower drum hole 1a becomes larger by several mum than at the time of the room temperature. On the other hand, the upper drum shaft 5 is cooled below -20 deg.C, and its outer diameter becomes smaller by several mum than at the time of the room temperature, and it turns into the relation of the loose fit of the clearance of several mum to the lower drum hole 1a. Thus, it can be fixed highly precisely, and the correction working of the lower drum 1 becomes unnecessary, and the shaft press fitting device becomes unnecessary as well.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides an image reproducing drum for which an upper drum of an image reproducing drum rotates in a lower drum hole penetrating the lower drum of an image reproducing drum used in a VTR. This invention relates to a VTR drum shaft insertion method for inserting an upper drum shaft that becomes the shaft of the camera.

[Conventional technology]

A conventional upper drum shaft is press-fitted into a lower drum hole. First, we will briefly explain the lower drum hole, upper drum shaft, etc. during press-fitting.

The lower drum is made of a material such as aluminum, and has a lower drum hole having an inner diameter of about 3 mm at normal temperature and having a center axis that coincides with the center axis of the outer peripheral surface of the lower drum, passing through the center of its bottom. In addition, a circular disc-shaped rotary
The transformer fixing leg is fixed to the inner bottom surface of the lower drum with an adhesive, with its center axis aligned with the center axis of the lower drum hole.

On the other hand, there is a one-liter drum shaft made of steel, which has an outer diameter that provides an interference fit with the above-mentioned drum hole at room temperature, and an annular disc-shaped rotary transformer. A rotating part is rotatably attached to the center of the seventeenth drum shaft via a bearing with its central axis aligned with the central axis of the upper drum shaft.

Next, the conventional press-fitting method will be explained. The lower drum is held on a holding stand of the @Kokyu device, while the upper end of the upper drum shaft is held by the gripping means of the shaft press-fitting device. . Next, the gripping means is moved, and the upper drum shaft is press-fitted into the lower drum hole at room temperature so that the center axis of the upper drum shaft and the center axis of the lower drum hole coincide.

After press-fitting, the gap between the fixed part of the rotary transformer of the top drum and the co-rotating part of the rotary transformer of the seventh drum shaft passes through the lower end surface of the upper drum shaft or the lower drum hole and reaches the stopper provided on the holding base. It is controlled by being pressed until it hits you.

[Problems to be Solved by the Invention] In the conventional shaft press-fitting method described above, during press-fitting, the inner wall of one drum hole may be scraped or deformed, or the shape of the lower drum itself may be deformed.
The center line of the lower drum shaft is relative to the center axis of the lower drum hole.
There are cases where there are several classifications. In this case, there is a problem in that the lower drum must be adjusted at an angle using the central axis of the upper drum shaft as a base ring.

- The range in which the upper end of the drum shaft can be gripped is only a few mm from the upper end, and the human device can grasp the upper end of this small range and align it with the center axis of the lower drum hole. A large pressing force must be used to align the center edge lines of the L and drum shafts with high precision. 17. Therefore, the shaft press-fitting device is very expensive, heavy, and has the problem that it is not easy to maintain its high accuracy.

Furthermore, the stopper provided on the holding base needs to be firmly fixed so that it will not easily move even if a large press force is applied through the upper drum shaft, so the insertion amount of the drum shaft can be adjusted with high precision. Providing an adjustable stop means
The problem is that it is extremely difficult.

Furthermore, if a relief shape or the like is formed in the lower drum hole in order to reduce the large pressing force, there is a problem in that the manufacturing cost of the lower i-ram increases by one unit.

The present invention has been made in view of the above-mentioned problems of the conventional technology, and it is possible to insert the upper drum shaft into the lower drum hole with high precision, eliminate the need for corrective machining of the lower drum, and maintain high precision. It is an object of the present invention to provide a method for inserting a VTR drum shaft that does not require a difficult, large and heavy shaft press-fitting device and that allows the amount of insertion of the upper drum shaft to be adjusted with high precision.

[T stage for solving problems]

To achieve the above object, the VTR drum shaft insertion method of the present invention is as follows: (11) The drum shaft is processed in advance so that it has a tight fit relationship with the top drum hole at room temperature, and the bottom drum (nD) is inserted into the bottom drum. Heat it and keep it at about 80℃, and then heat the drum shaft to -20℃.
The upper drum shaft, which has been cooled to below -20°C, is inserted into the lower drum hole, which has been heated to approximately 80°C, while the element 1+l is maintained in a loose fit. , (The feature is that it is extracted.

Further, in the VTR) ram@pressing method of the present invention,
The linear expansion coefficient of the material of the lower drum is 0.2 x 10-4 mm/
"C to 0.23X 10-4 mm/"C, and the coefficient of linear expansion of the material of the drum shaft is 0. IX1
0-4mm/''C or more, or the lower drum is made of aluminum and the drum shaft is made of steel.

Further, in each of the VTR drum shaft insertion methods of the present invention, the clearance fit between the upper drum shaft of -20 DEG C. or lower and the lower drum hole of about 80 DEG C. may be 1 or 2 .mu.m.

[For production]

In the VTR drum shaft insertion method of the present invention configured as described above, for example, the lower drum through which the lower drum hole with an inner diameter of 3 mm penetrates is made of a material such as aluminum, and When the upper drum shaft with an outer diameter that forms an interference fit with an interference of several μm at room temperature is made of a material such as steel, the lower drum is heated by a heating means and maintained at approximately 80°C. Therefore, the inner diameter of the lower drum hole becomes several μm larger than that at room temperature. Further, the temperature of about 80° C. is lower than the upper limit of the heat resistance temperature of the adhesive that fixes the rotary transformer fixing portion to the lower drum.

On the other hand, the upper drum shaft is cooled to below -20°C by the cooling means, and its outer diameter becomes several micrometers smaller than at room temperature, and the upper drum shaft is a loose fit with a clearance of several micrometers relative to the lower drum hole at about 80°C. be put in a relationship.

The upper drum shaft below -20° C. is quickly inserted into the lower drum hole at about 80° C. while the clearance fit relationship is maintained, so during the insertion, the upper drum shaft
It is not restricted by the lower drum hole and is inserted with only a slight insertion force until it comes into contact with a stopper provided on the holding base.

After insertion, when the temperature returns to room temperature, the fit between the lower drum hole and the upper drum shaft returns to the original tight fit relationship with an interference of several μm, so the upper drum shaft remains firmly fixed to the lower drum hole. becomes.

〔Example〕

An embodiment of the present invention will be described based on the drawings.

First, the lower drum of the image forming drum, the upper drum shaft, the shaft insertion device, etc. used in carrying out the method of this embodiment will be described in order.

In FIG. 3(C), the lower drum 1 made of aluminum is in the shape of a very shallow hook having an outer peripheral surface 1c.

The lower drum hole 1a penetrating the center of the bottom of the lower drum 1 and the outer circumferential surface 1c are lathed at the same time so that they are aligned with each other at the center [i
! are in agreement. Further, since the reference surface 1b, which will be described later, is lathed at the same time as the lower drum hole 1a and the outer circumferential surface 1c, it is a plane that is orthogonal to the center axis of the lower drum hole 1a and the outer circumferential surface IC with high accuracy. Lower drum hole 1a
is the inner diameter φ at room temperature (hereinafter, "normal temperature" is 20℃)
The inner peripheral edge of the upper end thereof is chamfered, and acts as a guide when the lower end surface of the upper drum shaft 5, which will be described later, is inserted. A reference surface 1b perpendicular to the center line of the lower drum hole 1a and a cylindrical protrusion 1d projecting downward in the drawing from the reference surface 1b are formed on the bottom surface of the lower drum 1 facing downward in the drawing. and the protrusion 1
The central axis of d coincides with the central axis of the lower drum hole 1a. The annular and disc-shaped rotary transformer fixing part 2 is
It is fixed to the bottom surface of the lower drum 1 facing upward in the figure with an adhesive (not shown) with its center axis aligned with the center axis of the lower drum hole 1a.

Also. The inner diameter of the lower drum hole 1a, which is heated from room temperature and maintained at 80° C., is calculated as follows.

Expansion amount = 0.207X10-'X3.000x (8
0-20) = 0.0037 (mm) Here, 0.207xlO-' (mm/-C) is the linear expansion coefficient of aluminum, 3.000 (mm) is the inner diameter of the lower drum hole 1a at room temperature, ( 80-20) ("C) is the temperature difference. Therefore, the inner diameter of the F drum hole 1a at 80°C is
The diameter is 3.0037 mm.

In FIG. 3(B), the steel upper drum shaft 5 has an outer diameter φ3.003 mm that provides an interference fit with the drum hole 1a at room temperature with an interference of 3 μm.
The periphery of the lower end face is chamfered. The housing 6 is rotatably attached to the center of the upper drum 5 via a bearing 4, and the annular and disc-shaped rotary transformer rotating part 3 has its center axis aligned with the center axis of the upper drum #i5. and is attached to the housing 6. Further, the outer shape of the upper drum shaft 5 cooled from room temperature to -20° C. is calculated as follows.

Fat swelling amount = 0.110xlO-'x3.003X (-
20-20) = -0,0013 (mm) Here, 0.110 x 10-' (mm7℃) is the coefficient of linear expansion of the steel, and 3.003 (mrn) is the coefficient of linear expansion of the upper ram shaft 5 at room temperature. The outer diameter (-20-20) ("C) is the temperature difference. Therefore, the outer diameter of the upper drum shaft 5 at -20°C is φ
It becomes 3.0017 mm.

Next, a shaft insertion device used to carry out the method of the present invention will be explained.

In FIG. 1(A), the holding stand 10 includes a heat insulating material 22a,
The lower drum 1 is fixed to the base 22 via the base 22b, and the lower drum 1 is placed on the upper surface 10a of the base 22 with the reference surface 1b in contact with the lower drum 1. At the center of the holding table 10, there is a lower drum 1.
A hole 10b having an inner diameter large enough to fit the protrusion 1d of the hole 10b.
passes through the top and bottom. The hole 10b allows the positioning of the lower drum hole 1a on the holding stand 10 by ±0.1 mm by fitting the protrusion 1d into the upper end of the hole 10b when the lower drum 1 is placed on the holding stand 10. It is intended to be carried out with a certain degree of accuracy.

The stopper 14 is piston-shaped and has an upper surface 14a formed therein, and is movable in the direction of the central axis of the lower drum hole 1a of the lower drum 1 placed on the holder 10 into the hole 10b of the holder 10. The position adjusting means 13 attached to the base 22 is pressed by its own weight through the heat insulating material 22c. The position adjusting means 13 is a well-known device that adjusts the position of the stopper 14 with high precision through the heat insulating material 22c using a piezoelectric effect.

Six cylindrical petals a to iff, which are a plurality of heating means including electric heating, fluid heating, etc., are embedded inside the holding table 10, and a temperature sensor 12 is installed inside the holding table 10. It is buried near the upper end of the hole 10b. Each of the heaters 11a to iff and the temperature sensor 12 are connected to a controller (not shown), and are controlled by the controller to heat the holding table 10 and heat the lower drum 1 placed on the holding table 10 to about 80°C. can be kept.

On the other hand, the gripping means 15 fits into the tip of each of the pair of gripping members 15a and 15b, and the upper drum shaft 5
It grips the upper end (any known means can be used as long as it can grip the upper drum shaft 5), and the contact surfaces with the upper drum shaft 5 are each heat-insulated. Material 15C915d is fixed.

A hollow inner cylinder 16a is attached to the upper surface of the gripping means 15, and the inner cylinder 16a is fitted onto the outer surface 816b so as to be slidable in the direction of the central axis of the upper drum shaft 5.

The spring 16c is inserted into the inner cylinder 16a and presses the upper surface of the gripping means 15 and the upper surface of the inner portion of the outer portion i 16 b in a direction of pushing them apart. The sliding distance is
They are restricted by locking portions that engage with each other and are provided at the upper end of the outer peripheral surface of the cylinder 16a and the upper end of the inner peripheral surface of the outer cylinder 16b, respectively. The -F surface of the outer cylinder 16b is attached to the lower surface of the first flat plate 17a of the compliance mechanism 17.

Here, the compliance mechanism 17 will be explained.

In FIG. 1(B), the first flat plate 17a is a flat plate with a -1 side and a square bottom face, and the second flat plate 17b and the third flat plate 17e also have the same shape and the same material as the first flat plate 17a. Furthermore, the pair of first spring plates 17d and 17e and the pair of second spring plates 17f and 17g have the same shape and are made of the same material. The lower ends of a pair of 7g1 spring plates 17d and 17e are fixed to both opposite side surfaces of the first v-plate f7a with screws, respectively. The upper end portion is a second flat plate 17
They are fixed with screws or the like on opposite sides of b.

Furthermore, the lower end portions of a pair of second spring plates 17f and 17g are fixed to the remaining both sides of the second flat plate 17b with screws, respectively, and the second spring plates 17f and 17g of the pair,
The upper end portions of the third flat plate 17g are fixed to opposite side surfaces of the third flat plate 17c with screws or the like. The pair of first spring plates 17d, 17e are perpendicular to the first and second flat plates 17a, 17b, respectively, and similarly, the pair of second spring plates 17'f, 17g are also perpendicular to the second and third flat plates 17b. , 17c. Said first flat plate 1
7a, the second flat plate 17b, and the third flat plate 17c are parallel to each other. The compliance mechanism 17 is configured in this way.

The upper surface of the third flat plate 17c of the compliance mechanism 17 is
It is attached to a moving mechanism 18 of an industrial robot, and the moving mechanism 18 is attached to a lower drum hole 1 placed on a holding table 10.
It is movable in the direction of the central axis of a and in the direction perpendicular to the central axis.

The cooling means 30 shown in FIG.
The moving mechanism 1 has an open upper part.
It is within the movement range of 8. The upper drum shaft 5 is moved by the moving mechanism 18 and cooled to below -20° C. while being placed on the stand 30a of the cooling means 30.

Here, the operation of the compliance mechanism 17 will be explained. During insertion, even if the position of the upper drum shaft 5 gripped by the gripping means 15 is slightly shifted from the lower drum hole 1a, each flat plate 17a of the compliance mechanism 17,
By relatively moving 17b and 17c,
The positional shift of the gripping means 15 is absorbed, and insertion can be performed without any trouble. Furthermore, when the upper drum shaft 5 placed on the stand 30a of the cooling means 30 is gripped by the gripping means 15, the positional shift of the gripping means 15 is similarly absorbed. When no external force is applied to the compliance mechanism 17, the flat plates 17a, 17b, and 17c always return to their respective equilibrium positions. Furthermore, it will be more effective if each of the flat plates 17a, 17b, and 17c are fixed so that they do not vibrate while the moving mechanism 18 is moving at high speed.

Next, the inner cylinder 16a, the outer cylinder 16b and the spring 16c
The operation of the components will be explained. During insertion, even after the moving mechanism 18 brings the lower end surface of the upper drum shaft 5 into contact with the upper surface 14a of the stopper 14, it is further lowered by an appropriate distance, and the inner cylinder 16a and the outer cylinder 16b are moved by the appropriate distance. ,
It is relatively moved in the shrinking direction. At this time, the lower end surface of the upper drum shaft 5 or the stopper 1 is
Press the upper surface 14a of 4. As a result, the stopper 14
The upper drum shaft 5 is inserted into the lower drum hole 1a by a predetermined insertion amount without damaging the position adjusting means 13 and the like.

Finally, the method of this embodiment using the above-mentioned shaft insertion device will be explained.

First, the distance 11LI (see FIG. 3(C)) from the reference surface 1b of the lower drum 1 to the upper surface of the rotary transformer fixing part 2 is measured at room temperature, and the distance 11LI from the lower end surface of the upper drum shaft 5 to the upper surface of the rotary transformer rotating part 3 is measured. Distance to the bottom surface is 1! IL2 (
(See FIG. 3(B)) is measured at room temperature. Next, considering the predetermined gap between the upper part of the rotary transformer fixing part 2 and the lower surface of the rotary transformer rotating part 3, as well as the thermal expansion of the lower drum 1 and the upper drum shaft 5 at the time of insertion, the Distance 111iL3 from the lower end surface of the upper drum shaft 5 to the reference surface 1b of the lower drum 1 (Fig. 3(A)
)). Next, the position adjusting means 13 (see FIG. 1(A)) is operated to adjust the distance from the top surface 14a of the stopper to the top surface of the holding base 10 to be equal to the distance L3.

After completing the above work, attach the lower drum 1 to each heater 11a~
It is placed on a holding table 10 heated by IF and kept at about 80°C. The inner diameter of the lower drum hole 1a at about 80°C at this time is
The diameter is approximately 3.0037 mm.

Further, the upper drum shaft 5 is placed on the stand 30a of the cooling means 30 and cooled to below -20"C. At this time, the outer diameter of the upper drum shaft 5 below -20"C is φ3.0017 mm or a smaller diameter. This results in a loose fit relationship with the lower drum hole 1a at the target temperature of 80° C. with a clearance of about 2 μm or more.

Next, the upper end of the upper drum shaft 5 below -20° C. is gripped by the gripping means 15, and the upper drum IIk5 is
The moving mechanism 18 moves the target placed on the holding table 10 from the stand 30a of the cooling means 3o at high speed to above the lower drum hole 1a of 80° C., and then lowers the target to the lower drum hole 1.
Insert it quickly into a. At this time, upper drum I! Il]5
The lower end surface of the stopper 1 receives the load of the spring 16c
-1- to the position where the upper surface 14a of 4 is pressed.
It is assumed that the drum shaft 5 is lowered. This results in
The clearance between the rotary transformer fixed part 2 of the lower drum 1 and the rotary transformer rotation @2 of the upper and lower ram shafts 5 can be managed with high precision.

In addition, the insertion speed of the moving mechanism 18 when inserted into the upper drum shaft 5 or the lower drum hole 1a is 200 m.
m/sec ~500 mm/sec
It shall be within the range of c. By quickly inserting at an insertion speed within this range, insertion can be completed while the above-mentioned clearance fit relationship is maintained.

After the insertion is completed, the temperature of the upper drum #I5 rises to the temperature of the lower drum 1 within a few seconds, and the second drum shaft 5 yields and becomes fixed to the lower drum 1.

When the upper drum shaft 5 and the lower drum shaft 1 return to room temperature, they return to their tight spring relationship with an interference of 3 μm.

(Effects of the Invention) Since the present invention is configured as described above, it produces the effects described below.

During insertion, insertion is performed with only a small insertion force, so a large pressing force is not required, and the upper drum shaft, lower drum hole, or lower drum will not be deformed when inserting. The center axes of the upper drum shaft and lower drum hole are aligned with each other with a high precision that is almost the same as the machining precision of the upper drum shaft and lower drum hole.
The upper drum shaft can be fixed to the lower drum hole, and there is no need to modify the lower drum. In addition, since a large pressing force is not required, the insertion amount of the upper drum shaft into the lower drum hole can be set freely, and the clearance between the rotary transformer fixed part and the rotary transformer rotating part can be managed with high precision. .

These features make it possible to manufacture an image reproducing drum that can transmit VTR tape signals from the upper drum to the lower drum with even higher quality.

Further, since the temperature of the heated lower drum is about 80° C., there is no adverse effect of heat on the lower drum, typified by the adhesive on the lower drum.

Furthermore, the axial press-fitting device, which is very expensive, large and heavy, is also inconvenient.

[Brief explanation of the drawing]

FIG. 1(A) is a cross-sectional view of a main part of a shaft insertion device used in an embodiment of the present invention, FIG. 1(B) is a perspective view of the compliance mechanism of the shaft insertion device, and FIG. 2 is a perspective view of the compliance mechanism of the shaft insertion device. A cross-sectional view of the cooling means of the shaft insertion device, FIG. 3 (A) is a cross-sectional view showing the upper drum shaft inserted into the lower drum hole, and FIG. 3 (B)
Figure 3(C) is a cross-sectional view showing the 1□1-ram shaft and the drum hole. 1... Lower drum, 1a... Lower drum hole, 1b.
...Reference plane, lc...outer circumference +/+4. 2... Rotary transformer fixing part, 3... Rotary transformer rotating part, 4... Bearing, 5... Five drum shafts, 6... Housing, 10... Holding base, 10a...
Upper surface, 10b... hole, 11a, ltb, tic,
lid, 1! e. 11f, 13, 14a, 15a. 15 c. 16a ・ 16c ・ 17 ・ ・ 17a ・ 17c ・ 17d. 17 f. 18 ・ ・ 22a. 30...Heater, 12...Temperature sensor, Position adjustment means, 14...Stopper,...Top surface, 15...
- Gripping means, isb...gripping member, 15d...insulating material,...inner cylinder, 16b...outer cylinder,...spring, -compliance mechanism,...1st) P plate, 1 '7 b ...Second flat plate, ...Third flat plate, 17e...First spring plate, 17g...Second spring plate, ・Movement mechanism, 22b, 22cm --Insulating material, ・Cooling means, 30a...・Stand.

Claims (1)

[Claims] 1. The upper drum shaft is processed in advance so that it has a tight fit relationship with the lower drum hole at room temperature, and the lower drum is heated and kept at about 80°C; The upper drum shaft is cooled to -20°C or lower, and the upper drum shaft cooled to -20°C or lower is heated to about 8°C.
A VT characterized by being quickly inserted into a lower drum hole heated to 0°C while maintaining a loose fit relationship.
How to insert R drum shaft. 2. The linear expansion coefficient of the material of the lower drum is 0.2 x 10^-^
The range is from 4mm/℃ to 0.23×10^-^4mm/℃, and the linear expansion coefficient of the material of the upper drum shaft is 0.1×
VT according to claim 1, which is 10^-^4mm/°C or more.
How to insert R drum shaft. 3. The method for inserting a VTR drum shaft according to claim 1, wherein the material of the lower drum is aluminum and the material of the upper drum shaft is steel. 4. The VTR drum shaft insertion method according to claim 1, 2 or 3, wherein the clearance fit between the upper drum shaft at -20 DEG C. or lower and the lower drum hole at about 80 DEG C. is 2 .mu.m.