JP2786183B2 - Disk chucking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order. A Industrial field B Outline of the invention C Conventional technology D Problems to be solved by the invention E Means for solving the problems F Function G Example G-1 Configuration of the example (FIG. 1) G-2 Experiment for confirming the operation and effect of the embodiment and the result thereof (FIGS. 2A and B) G-3 Modification H Effect A of the present invention Industrial application field The present invention is provided in a disc player or the like. The present invention relates to a disk chucking device that abuts against a disk placed on a turntable and fixes the disk on the turntable. B SUMMARY OF THE INVENTION The present invention is directed to a disk pressing surface portion that abuts around a center portion of a disk placed on a turntable and presses the disk toward the turntable, and an end portion opposite to the disk pressing surface portion. And a thrust receiving member having a clamp member pressing surface portion that abuts against the distal end of the protrusion portion of the clamp member and presses the same toward the disk pressing surface side. In the chucking device, at least the protrusion of the clamp member is formed of one of polyacetal and polybutylene terephthalate, and the thrust receiving member is formed of the other of polyacetal and polybutylene terephthalate. , Clamp member and thrust receiving member are easy to manufacture and inexpensive In addition, at the time of rotation of the clamp member accompanying the rotation of the turntable, under a non-lubricated state, melting of the protrusion of the clamp member and the clamp member pressing surface of the thrust receiving member can be avoided, Further, the wear of both can be made extremely small. C. Description of the Related Art In a disk player, a disk as an information recording medium is mounted on a turntable and rotated at a predetermined rotation speed, and information is recorded or recorded on a recording track portion of the rotating disk. The information recorded in the unit is reproduced. In such a case,
To mount the disc on the turntable, the disc is placed on the turntable with the center of the disc corresponding to the rotation axis of the turntable, and the disc is brought into contact with the disc so that it is held by the turntable. It is made fixed on a turntable by a chucking device. FIG. 3 shows a state in which a disk is mounted on a turntable using a conventionally proposed disk chucking device. In FIG. 3, the disk D mounted on the turntable 11 is fixed on the turntable 11 by the disk chucking device 21. The turntable 11 has a rotating shaft 13, a center ring member 15 disposed around the rotation shaft 13 and engaged with the center hole Da of the disk D, and a disk table portion 17a disposed around the center ring member 15. And a disk support member 17 that rotates together with the rotating shaft 13. The centering member 15 and the disc support member 17
Between them, a coil spring 19 is contracted. The disc D has its center hole Da fitted in the centering member 15, and the periphery of the center hole Da is supported by the disc table portion 17a.
Placed on top. The disc capping device 21 includes a bearing member 23 fitted to the tip of the rotating shaft 13 provided on the turntable 11, a clamp member 25 arranged to surround the bearing member 23 and to contact the disc D. And a holding member 27 that movably holds the clamp member 25. The clamp member 25 is opposed to the disk table portion 17a of the turntable 11, is in contact with a peripheral portion of the central hole Da of the disk D supported by the disk table portion 17a, and presses the disk D, and a disk pressing surface portion 29.
The disk pressing surface portion 29 is fixed to the end opposite to the opposite side, and has an end surface portion 33 in which a steel ball 31 is partially exposed and embedded in a central portion, and a portion other than the steel ball 31 is For example, it is formed of a synthetic resin. A projection protruding toward the inside of the clamp member 25 is provided at a central portion of the end surface portion 33, and around the protrusion, the projection is compressed between the end surface portion 33 and the bearing member 23. A pulling 35 is provided. Further, the holding member 27 is provided with a clamp member engaging portion 37 that engages with the clamp member 25 to hold the same,
When the disc pressing surface portion 29 of the clamp member 25 comes into contact with the peripheral portion of the center hole Da of the disc D, the clamp member
25 abuts against a steel ball 31 arranged at the center of the end face portion 33, and presses the steel ball 31 against the disc pressing surface portion of the clamp member 25.
A thrust receiving member 39 having a clamp member pressing surface portion 39a that presses toward the 29 side is provided. This thrust receiving member 39
Is formed, for example, of a synthetic resin material in which a ceramic plate forming the clamp member pressing surface portion 39a is embedded. With such a configuration, the disc pressing surface portion 29 of the clamp member 25 is positioned at the center hole D of the disc D supported by the disc table portion 17a of the turntable 11.
In the state in which the thrust receiving member 39 disposed on the holding member 27 is in contact with the peripheral portion of a, the clamp member pressing surface portion 39a is brought into contact with the steel ball 31 disposed on the clamp member 25, and the thrust receiving member 39 is disc-shaped. The disk D is pressed toward the disk table 17a of the turntable 11 by the disk pressing surface 29 of the clamp member 25, and is fixed on the turntable 11. FIG. 4 shows the disk chucking device 21 described above.
Disc chucking device 2 with a different configuration
1 'is shown. In this example, the thrust receiving member 39 ′ provided on the holding member 27 and abutting on the steel ball 31 disposed at the central portion of the end surface 33 of the clamp member is resistant to synthetic resin such as polyacetal, for example. It is integrally formed of a synthetic resin material having relatively excellent wear properties. In this case, one surface of the thrust receiving member 39 'is formed of a steel ball.
It directly comes into contact with 31 to form a clamp member pressing surface portion 39 '. D Problems to be Solved by the Invention However, in the conventional disk chucking device as described above, for example, in the case of the one shown in FIG. 3, the thrust receiving member is arranged on the clamp member. Is formed of a synthetic resin material in which a ceramic plate that forms a clamping member pressing surface portion that abuts against the steel ball is embedded, so that wear between the steel ball and the thrust receiving member can be reduced, and good rotational characteristics can be obtained. However, there are drawbacks in that the manufacturing process of the thrust receiving member is complicated, the material cost is increased, and the thrust receiving member is expensive. On the other hand, in the case of the one shown in FIG. 4, the thrust receiving member is integrally formed of, for example, polyacetal, so that the manufacturing process is simplified and the thrust receiving member can be obtained at a low cost. At such a level, there is a problem that the wear of the pressing surface of the clamp member in contact with the steel ball in the thrust receiving member becomes conspicuous, and good rotational characteristics cannot be obtained. In view of such a point, the present invention provides a disk pressing surface portion that contacts a disk placed on a turntable and presses the disk toward the turntable, and is provided at an end opposite to the disk pressing surface portion. And a thrust receiving member having a clamp member pressing surface portion that abuts against the distal end of the protrusion portion of the clamp member and presses the same toward the disk pressing surface portion side. It is assumed that the receiving member can be obtained at low cost, cost reduction is achieved, and at the time of rotation of the clamp member accompanying rotation of the turntable, in an unlubricated state,
Provided is a disk chucking device that does not involve melting of a protrusion of a clamp member and a clamp member pressing surface of a thrust receiving member, and has extremely small wear, thereby obtaining good rotational characteristics. The purpose is to do. E Means for Solving the Problems In order to achieve the above-mentioned object, a disk chucking device according to the present invention is arranged such that the disk chucking device contacts the periphery of a center portion of a disk placed on the turntable and moves the disk to the turntable side. The disk pressing surface portion is provided at a position opposite to the disk pressing surface portion on the extension of the rotation axis of the turntable in a state where the disk pressing surface portion is in contact with the disk. And a thrust receiving member having a clamp member pressing surface portion that abuts on the tip of the protrusion portion of the clamp member and presses the protrusion portion toward the disk pressing surface side. The clamp member has at least a protrusion formed of one of polyacetal and porbutylene terephthalate. Rutotomoni thrust receiving member is made to have been formed by the other of the polyacetal and polybutylene terephthalate. In the disk chucking device according to the present invention configured as described above, since at least the projecting portion of the clamp member and the thrust receiving member are both formed of synthetic resin, they are easy to manufacture, It is said that it can be obtained at low cost. In addition, the synthetic resin forming at least the protrusion of the clamp member and the thrust receiving member having the clamp member pressing surface that comes into contact with the clamp member is selected such that one is polyacetal and the other is polybutylene phthalate. When the clamp member is rotated, the protrusion of the clamp member and the clamp member pressing surface of the thrust receiving member are not melted in a non-lubricated state, and the wear of both is extremely small. Will be. G. Embodiment G-1 Configuration of Embodiment (FIG. 1) FIG. 1 shows an example of a disk chucking apparatus according to the present invention, which is used to attach a disk to a turntable similar to that shown in FIG. Shows the state where the attachment has been made. In FIG. 1, the portions corresponding to the respective portions shown in FIG. 3 are denoted by the same reference numerals as those in FIG. 3, and redundant description thereof will be omitted. In the disk chucking device 41 shown in FIG. 1 as an example of the disk chucking device according to the present invention, the disk D supported by the disk table portion 17a is opposed to the disk table portion 17a of the turntable 11. Of the clamp member 25 having the disk pressing surface portion 29 for pressing the disk D by abutting the peripheral portion of the central hole Da, the end surface portion 51 fixed to the end opposite to the disk pressing surface portion 29, Including the projection 53 provided at the central portion, one of polyacetal and polybutylene terephthalate, for example, polyacetal is integrally formed. The projection 53 provided at the center of the end face 51 is provided on the rotating shaft of the turntable 11 in a state where the disc pressing surface 29 of the clamp member 25 is in contact with the periphery of the center hole Da of the disc D. It is arranged at a position that is an extension of 13 and its tip forms a part of a spherical surface having a relatively large radius. For example, the projection 53 has a base having a diameter of about 1.5 to 3.0 mm and a tip of the projection 53 forming a part of a spherical surface having a radius of about 50 mm or more. In addition, a projection protruding toward the inside of the clamp member 25 is also integrally formed and provided at a central portion of the end face portion 51. Around the projection, a contraction is made between the end face portion 51 and the bearing member 23. A mounted coil spring 35 is provided. Further, the thrust receiving member 55 provided on the holding member 27 having the clamp member engaging portion 37 that engages with the clamp member 25 to hold the same is provided with the other of polyacetal and polybutylene terephthalate, for example, polybutylene. It is made as one piece by terephthalate. The thrust receiving member 55 integrally formed of the polybutylene terephthalate has an end surface portion of the clamp member 25 when the lower surface portion of the thrust receiving member 55 contacts the peripheral portion of the center hole Da of the disk D when the disk pressing surface portion 29 of the clamp member 25 abuts.
51 abuts against the tip of a projection 53 arranged at the center of the disc 51, and presses the projection 53 to the disc pressing surface 29 of the clamp member 25.
To form a clamp member pressing surface portion 55a that presses the pressing member. That is, in the disk chucking device 41, when the chucking state of fixing the disk D supported by the disk table portion 17a of the turntable 11 on the disk table portion 17a is taken, the disk pressing surface portion
A clamp member pressing surface of a thrust receiving member 55 formed of polybutylene terephthalate is provided at the tip of a projection 53 formed of polyacetal of the clamp member 25 which is to press the peripheral portion of the center hole Da of the disk D by 29. 55a comes into contact with and presses it. Thereby, the clamp member 25 rotates with the rotation of the turntable 11, and as a result, the protrusion 53 of the clamp member 25
However, even if the tip is rotated while being pressed by the clamp member pressing surface portion 55a of the thrust receiving member 55, the protrusion 53 and the clamp member pressing surface portion 55a do not melt, and Wear is also extremely small, and excellent rotational characteristics can be obtained. In addition, the end face portion 51 including the above-mentioned protrusion 53 may be formed of not only a simple polyacetal but also a polyacetal mixed with 10% by weight of Teflon (hereinafter, referred to as polyacetal + T). The characteristics are further improved. G-2 Experiment for confirming the operation and effect of the embodiment and the result thereof (FIGS. 2A and B) Hereinafter, the protrusion 53 formed of polyacetal or polyacetal + T in the clamp member 25 and the polybutylene terephthalate contacting the tip thereof will be described. Clamp member pressing surface portion 55a of formed thrust receiving member 55
Thus, the point of obtaining excellent rotation characteristics will be described based on experimental results. As shown in FIG. 2A, the inventor of the present application has proposed a rod-shaped body Si (having a diameter d) having a circular cross section with a flat end at the tip and a plate having a flat surface in contact with the tip of the rod-shaped body Si. The rod-shaped body Si is formed of polyacetal and polyacetal + T, and the plate-shaped body Qi is formed of polybutylene terephthalate.
With the flat surface of the plate Qi pressed against the tip of the rod Si with a force F (kg), the rod Si is rotated at a rotation speed N (rpm). The pressure P acting between the rod-shaped body Si and the plate-shaped body Qi is P = F · 4 / (π ·
d ² ) (kg / cm ² ) and the value of the maximum peripheral velocity V = π · N · d / 60 (cm / sec) at the tip of the rod-shaped body Si based on the rotation speed N (hereinafter, limit P
−V value) was obtained at room temperature, and the results as shown in FIG. 2B were obtained. FIG. 2B shows a graph in which the horizontal axis represents the maximum peripheral speed V and the vertical axis represents the pressure P. Here, a curve Ca indicated by a broken line indicates, for example, that the rotational speed N is 1800 rpm. And the force F
In the case of 0.9 kg, that is, when the condition between the protrusion of the clamp member in the disc chucking device applied to a normal video disc player and the thrust member abutting on it, the rod-shaped body Si and The required minimum limit PV value for the plate-like body Qi is expressed,
Further, the range where the diameter d of the rod-shaped body Si is 0.15 to 0.3 (cm) is shown as the practical range α. In FIG. 2B, a curve Cb represents the result obtained when the rod-shaped body Si and the plate-shaped body Qi are both formed of polyacetal, obtained by the above-described experiment, with respect to the curve Ca. The result when the rod-shaped body Si is formed of polyacetal and the plate-shaped body Qi is formed of polybutylene terephthalate is represented by a curve Cc. Further, the rod-shaped body Si is formed of polyacetal + T and the plate-shaped body Qi is formed of polybutylene. The result in the case of being formed by terephthale is represented by a curve Cd. From the results shown in FIG. 2B, the results represented by the curves Cc and Cd exceed the necessary minimum limit PV value represented by the curve Ca in the practical range, and the rotational speed N is 18
00 rpm and the force F was 0.9 kg, that is, the condition between the protrusion of the clamp member and the thrust receiving member abutting on the clamp member in the disc chucking device applied to a normal video disc player. Thus, it is understood that the rod-shaped body Si is formed of polyacetal, and when the plate-shaped body Qi is formed of polybutylene terephthale, the rod-shaped body Si is formed of polyacetal. It can be seen that the plate-shaped body Qi has a higher solubility limit than when it is formed of polybutylene terephthalate. From the above experimental results, as described above, the clamp member
Under the condition that the thirty-five projections 53 are formed of polyacetal or polyacetal + T, and the thrust receiving member 55 having the clamp member pressing surface 55a abutting on the tip of the projection 53 is formed of polybutylene terephthalate,
A melting limit characteristic corresponding to the result represented by the curve Cc or Cd in FIG. 2B is obtained, and even when the clamp member 25 rotates with the rotation of the turntable 11, the protrusion is formed.
It is understood that the dissolution of the 53 and the clamp member pressing surface 55a does not occur. In addition, the inventor of the present application, as described above,
The first state in which the clamp member pressing surface 55a of the thrust receiving member 55 formed of polybutylene terephthalate abuts on the tip of the protrusion 53 formed of polyacetal in 25, and the polyacetal + T in the clamp member 25 Thrust receiving member formed of polybutylene terephthalate at the tip of projection 53
In each of the second states in which the 55 clamp member pressing surface portions 55a abut, the clamp member pressing surface portion 55a of the thrust receiving member 55 presses the projection 53 with a force of 0.8 kg,
As a result of an experiment in which the projection 53 was rotated at a rotation speed of 1800 rpm and the rotation was continued for 2000 hours, the amount of wear at the tip of the projection 53 in both the first state and the second state. Is approximately 130 μm, and it has been confirmed that the amount of the recessed abrasion of the clamp member pressing surface 55 a was extremely small, approximately 40 μm. As shown in FIG. 4, the clamp member pressing surface 39a 'of the thrust receiving member 39' made of polyacetal is formed on the steel ball 31 disposed at the center of the end surface 33 of the clamp member. When the contact is made, the clamp member pressing surface 39a 'of the thrust receiving member 39'
Presses the steel ball 31 with a force of 0.8 kg.
According to the results of an experiment in which the rotation was performed at a rotation speed of 1800 rpm, the amount of the recessed abrasion in the clamp member pressing surface portion 39a 'of the thrust receiving member 39' was approximately 350 [mu] m just by continuing the rotation for 600 hours. From such experimental results, as shown in the example shown in FIG. 1, the projection 53 of the clamp member 25 is formed of polyacetal or polyacetal + T, and the thrust having the clamp member pressing surface 55a contacting the tip of the projection 53. Under the condition that the receiving member 55 is formed of polybutylene terephthalate, the abrasion between the projection 53 and the clamp member pressing surface 55a caused by the rotation of the clamp member 25 with the rotation of the turntable 11 is extremely small. It is understood that. G-3 Modified Example In the example shown in FIG.
Although only the end face 51 provided with the projection 53 in 25 is made of polyacetal or polyacetal + T, the clamp member 25 is integrated with the end face 51 with the projection 53, and Clamp member
25 is polyacetal or polyacetal + T
May be formed. Further, the entire end surface portion 51 of the clamp member 25 where the protrusion 53 is provided, or the entire clamp member 25 including the end surface portion 51 with the protrusion 53 is formed of polybutylene terephthalate. The thrust receiving member 55 having the clamp member pressing surface 55a may be formed of polyacetal or polyacetal + T. In such a case, the same operation and effect as in the above-described example can be obtained. H Advantageous Effects of the Invention As is apparent from the above description, in the disk chucking device according to the present invention, a disk pressing surface portion for pressing the disk against the turntable by contacting the disk mounted on the turntable and At least a protrusion of a clamp member having a protrusion provided at an end opposite to the disk pressing surface, and a clamp member pressing contacting the tip of the protrusion of the clamp member and pressing it toward the disk pressing surface. Since both the thrust receiving member having the surface portion and the thrust receiving member are formed of synthetic resin, the clamp member and the thrust receiving member can be manufactured easily and inexpensively, and therefore, cost reduction can be achieved. Can be Moreover, the synthetic resin forming at least the protrusion of the clamp member and the thrust receiving member having the clamp member pressing surface portion abutting on the clamp member is selected such that one is polyacetal and the other is polybutylene terephthalate. When the clamp member rotates along with the rotation of the clamp member, the protrusion of the clamp member and the clamp member pressing surface of the thrust receiving member are not melted in a non-lubricated state, and the wear of both is extremely small. As a result, good rotation characteristics can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of a disk chucking device according to the present invention, together with a disk and a turntable chucked by the chucking device. FIGS. FIG. 3 is a diagram for explaining an experiment conducted to confirm the operation and effect of the disk chucking device and a result thereof. FIG. 3 is a diagram showing a disk and a turntable chucked by using a conventionally proposed disk chucking device. FIG. 4 is a sectional view showing a portion of another conventionally proposed disk chucking device. In the figure, 11 is a turntable, 25 is a clamp member, 27 is a holding member, 29 is a disk pressing surface portion, 41 is a disk chucking device, 51 is an end surface portion, 53 is a projection, 55 is a thrust receiving member, and 55a is a clamp. The member pressing surface portion D is a disk.

Claims (1)

(57) [Claims] A disk pressing surface for pressing the disk against the turntable by contacting the periphery of the center of the disk mounted on the turntable; and, at an end opposite to the disk pressing surface, the disk A clamp having a projection provided at a position on the extension of the rotation axis of the turntable under a state where the pressing surface is in contact with the disk, wherein at least the projection is formed of polyacetal or polybutylene terephthalate A thrust receiving member formed of polybutylene terephthalate or polyacetal, the member having a clamp member pressing surface that abuts on the tip of the protrusion of the clamp member and presses the protrusion toward the disk pressing surface; A disk chucking device comprising: