JPH0726825A - Shaft lock device and manufacturing method thereof - Google Patents

Abstract

PURPOSE:To make compact and lightweight a shaft lock device, to eliminate the application of oil and the like such as grease oil, etc., and, at the same time, manufacture it at a low cost. CONSTITUTION:The shaft lock device 1 is constituted of an inside shaft 2 of metal and an outside shaft 3 of resin formed together with the inside shaft 2 as a molding unit. A small diameter section for preventing the movement of the inside shaft 2 to the outside shaft 3 in the direction of the axis is formed in the shaft section of the inside shaft 2 inserted into the outside shaft 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used, for example, in a laptop type personal computer or a device such as a word processor.
The present invention relates to a shaft lock device for fixing a position of a display board at an arbitrary angle with respect to a main body including a keyboard and a manufacturing method thereof.

[0002]

2. Description of the Related Art Generally, a display panel such as a laptop personal computer or a word processor is normally stored in a closed state in a main body having a keyboard and the like, and is used in an opened state from the main body. When using the display panel, it may be difficult to see the characters and pictures on the screen due to the fact that light such as lighting is reflected on the screen of the display panel depending on the conditions of use and place of use. The position can be fixed at any angle with respect to.

As an axis lock device for fixing the position of the display board at an arbitrary angle with respect to the main body, for example,
For example, the one disclosed in Japanese Utility Model Laid-Open No. 1-135397 can be cited. This shaft lock device has a structure including a movable shaft, fixed shafts having the same diameter as the movable shaft and provided on both sides of the movable shaft, and springs externally fitted to the movable shaft and the fixed shaft. When the movable shaft rotates to one side,
The spring in the portion externally inserted in close contact with one fixed shaft contracts to generate a lock torque, and the spring in the portion externally inserted in close contact with the other fixed shaft expands to cause slip torque. The sum of the lock torque and the slip torque acts on the movable shaft to fix the position of the display board at an arbitrary angle.

[0004]

However, in the shaft lock device having such a structure, since the display board is positionally fixed at an arbitrary angle by the force of the spring, the spring must have a certain diameter. Therefore, there is a limit to downsizing and weight saving of the shaft locking device. In addition, since it is necessary that springs be externally fitted in close contact with the movable part and the fixed shafts on both sides of the central large diameter part of this movable shaft, the large diameter part and both sides of the movable shaft cannot be fixed. Since the outer diameters of the shafts are required to be substantially the same, there is a problem that the manufacturing cost is increased due to the need for parts such as springs and the demand for high dimensional accuracy. . Also,
For the type that uses slips between metals, it is usual to apply grease oil for rust prevention and smooth rotation, and this grease oil causes chemical changes in peripheral members. There was also a problem.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to reduce the size and weight, and to eliminate the need for oils for lubrication and rust prevention, thereby reducing the manufacturing cost. An object of the present invention is to provide a shaft locking device and a manufacturing method thereof that can reduce the possibility of deterioration over time due to the application of oils for lubrication and rust prevention while reducing the number of parts.

[0006]

In order to achieve the above object, a shaft lock device according to a first aspect of the present invention comprises an inner shaft and an outer shaft made of resin integrally molded with the inner shaft. It is characterized by that.

According to a second aspect of the present invention, in the shaft locking device, the inner shaft has a convex portion or a concave portion inside the outer shaft for preventing the inner shaft from moving in the axial direction with respect to the outer shaft, or It is characterized in that a combination of these convex portions and concave portions is formed.

According to a third aspect of the present invention, there is provided a method of manufacturing a shaft locking device, wherein a metal inner shaft and a resin outer shaft into which the inner shaft is inserted have surface friction resistance and are relatively rotatable. As a result, in the manufacturing method of the shaft locking device in which these shafts can be freely rotated and fixed at any angle, the inner shaft is placed inside the resin and the molding is integrally molded, so that the shaft and the inner shaft are integrated. And a step of forming an external shaft.

[0009]

According to the shaft lock device of the first aspect and the method of manufacturing the shaft lock device of the third aspect, the shaft lock device is constituted by an inner shaft and an outer shaft integrally molded with the inner shaft, The torque generated by the surface frictional resistance generated between the inner shaft and the outer shaft allows the inner shaft and the outer shaft to rotate relative to an arbitrary angle and be fixed.

Further, in the shaft locking device according to the second aspect of the present invention, the movement of the inner shaft in the axial direction with respect to the outer shaft is prevented by the convex portion and the concave portion formed on the inner shaft or the combination of the convex portion and the concave portion. You can

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, one embodiment of the present invention will be described with reference to FIGS.
Will be described with reference to. 1 is a perspective view showing the shaft locking device of this embodiment, FIG. 2 is a plan sectional view of the device, and FIG. 3 is a laptop personal computer to which the device is applied (hereinafter referred to as a laptop device). 3 is a perspective view in which a part of FIG.

In the drawings, reference numeral 1 is a shaft locking device, reference numeral 2 is an inner shaft, reference numeral 3 is an outer shaft integrally molded with the inner shaft 2, and the inner shaft 2 is made of metal such as steel. The outer shaft 3 is made of resin such as urethane, acetal, polycarbonate and nylon resin. As shown in FIG. 3, the shaft lock device 1 is mounted on the laptop device X by fixing the inner shaft 2 to the display board Z and the outer shaft 3 to the laptop device body Y. It is like this.

The inner shaft 2 has a shaft portion on the right side in FIG. 2 inserted into the outer shaft 3, and a shaft portion on the left side in FIG. 2 projects outward from the outer shaft 3. In order to prevent the inner shaft 2 from moving in the axial direction with respect to the outer shaft 3, the shaft portion inserted into the outer shaft 3 is provided with a small diameter portion (recess) 4 having a diameter smaller than the diameter of the shaft portion. The small-diameter portion 4 and the shaft portions (protruding portions) 8 on both sides thereof form step portions 5, 5. Further, the tip of the shaft portion projecting outward of the external shaft 3 has a shape cut out in parallel with the axis line, and as shown in FIG. An engagement portion 6 that rotates the inner shaft 2 itself by opening and closing is formed.

As for the outer shaft 3, the cylindrical portion 7 into which the inner shaft 2 is inserted, and the outer shaft 3 itself are connected to the laptop type device body Y.
And a mounting portion 9 extending laterally of the cylindrical portion 7 with a plate thickness smaller than the outer diameter of the cylindrical portion 7. The mounting portion 9 is provided with two mounting holes 10 and 10 spaced apart from each other.

In order to manufacture the shaft locking device 1 composed of the inner shaft 2 and the outer shaft 3, first, the inner shaft 2 molded into a predetermined shape is placed inside the resin serving as the outer shaft material, and is molded. Perform integral molding. Molding integral molding is performed by introducing a resin into a mold at a high temperature. Therefore, at high temperature, both the metal inner shaft 2 and the resin outer shaft 3 expand similarly, but when cooled to room temperature, the resin contracts with a large contraction rate, while the metal compares Since the outer shaft 3 contracts with a relatively small contraction rate, a force for tightening the inner shaft 2 by the outer shaft 3 acts. Therefore, when the outer shaft 3 and the inner shaft 2 are attempted to rotate relative to each other, torque due to surface frictional resistance is generated between them.

Therefore, in order to obtain a predetermined torque, the material of the inner shaft 2 and the outer shaft 3 is changed, the finish roughness of the metal surface of the inner shaft 2 is changed, or the surface treatment of the inner shaft 2 (plating, Change of friction coefficient due to surface modification accompanying coating, etc., and change of thermal expansion coefficient, or change of diameter of inner shaft 2 (inevitably the diameter of corresponding part of outer shaft 3 also changes), or protrusion 8 The diameter, length, number of parts, angle are changed, or molding conditions (temperature, speed, pressure, etc.) are changed. In addition, a method of giving initial "familiarity" by repeating mechanical relative motion after processing,
It is also possible to adjust the internal stress by processing at an appropriate temperature and stabilize the torque.

After the axis lock device 1 manufactured as described above is assembled into the laptop type device X, when the display board Z is opened / closed with respect to the laptop type device body Y, the outer shaft 3 and the inner shaft 3 are closed. Surface friction resistance is generated between the two and torque is generated between them. Here, when the torque applied to open and close the display board Z becomes larger than the torque due to the surface frictional resistance between the outer shaft 3 and the inner shaft 2, the inner shaft 2 moves with respect to the outer shaft 3. The display board Z is opened and closed by relative rotation. Further, when the added torque is removed to fix the display board Z, only the torque due to the weight of the display board Z acts between the outer shaft 3 and the inner shaft 2, and this torque is externally applied. The torque is smaller than the torque due to the surface frictional resistance between the shaft 3 and the inner shaft 2, and the position of the display board Z is fixed at an arbitrary angle.

Therefore, the torque due to the surface frictional resistance between the outer shaft 3 and the inner shaft 2 has the above-mentioned magnitude relationship, that is, the display board Z can be easily opened and closed by the force of a person, and the display board Z can be easily opened and closed. Torque is set to prevent it from moving under its own weight.

In the shaft lock device 1 of this embodiment, since the inner shaft 2 and the outer shaft 3 are integrally molded, a separate member for assembling these shafts becomes unnecessary. Further, since the external shaft 3 is provided with the attachment portion 9 to the laptop type device main body Y, a separate member for attachment is not necessary. Therefore, it is possible to reduce the size and weight of the shaft locking device 1 and reduce the manufacturing cost of the shaft locking device 1.

Also, from the viewpoint of the manufacturing process, a plurality of parts assembling processes that require precision are not required, so that the shaft locking device 1 can be easily assembled and only the function of reducing the number of parts is required. In addition, the manufacturing cost of the shaft lock device 1 can be reduced by the effect of reducing the number of manufacturing processes.

The small diameter portion 4 provided on the inner shaft 2 prevents the inner shaft 2 from moving in the axial direction with respect to the outer shaft 3. Z can be stably opened and closed. Further, the force generated in the axial direction at the step portions 5 and 5 of the small diameter portion 4 and the shaft portions 8 and 8 on both sides thereof can also be utilized as the torque due to the surface friction resistance.

Further, unlike the conventional shaft lock device, since the spring is not used for generating the torque, there is no damage such as a galling of the shaft, and it is not necessary to apply grease. Therefore, maintenance of the shaft lock device 1 becomes very easy, and there is no possibility that it will change over time.

In this embodiment, the inner shaft 2 is provided with the small diameter portion 4 for preventing the movement in the axial direction with respect to the outer shaft 3. However, instead of this structure, for example, the shaft portions 8 on both sides,
A large-diameter portion having a diameter larger than the outer diameter of 8 may be provided, and the shape is not limited to this as long as the protruding portion is formed inside the outer shaft 3. Further, the mounting portion 9 of the outer shaft 3 may have various shapes, and instead of providing the mounting portion 9 on the outer shaft 3, the whole outer shaft 3 is molded into, for example, a hexagonal column shape to form a laptop. It may be attached to the mold device X.

As a method of mounting the axis lock device, the laptop type device body Y is placed on the external shaft 3 side and the display board Z is attached.
The structure that attaches to the inner shaft 2 side has been described as an example,
It is also possible to have a structure in which the outer shaft side and the inner shaft side are attached in reverse. Further, instead of incorporating the shaft lock device 1 into the laptop device X, the internal shaft 2 may be directly inserted into the housing of the laptop device main body Y. Further, the axis lock device 1 is not limited to the laptop type device X and can be applied to various devices.

[0025]

As described above in detail, according to the shaft lock device of the first aspect and the method of manufacturing the shaft lock device of the third aspect, the metal inner shaft and the inner shaft and the molding are integrated. Since a shaft lock device having a molded resin external shaft can be realized, as in the conventional case,
It is not necessary to assemble separate inner shafts and outer shafts using fastening parts such as springs, and it is possible to reduce size and weight by reducing the number of parts of the shaft locking device, and not only the effect of reducing the number of parts, The manufacturing cost can be reduced due to the effect that the shaft locking device can be easily manufactured by the molding integral molding.

Further, since the shaft lock device operates smoothly due to the surface frictional resistance between the metal inner shaft and the resin outer shaft, oils for lubrication and rust prevention are applied as in the conventional case. It is also possible to eliminate the possibility that the shaft locking device will change over time due to the application of oils.

Further, in the shaft lock device according to the second aspect of the present invention, the protrusion formed on the inner shaft can prevent the inner shaft from moving in the axial direction with respect to the outer shaft. Can be performed stably.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a shaft lock device of the present invention.

FIG. 2 is a plan sectional view showing the same embodiment.

FIG. 3 is a partially cutaway perspective view of a laptop device to which the embodiment is applied.

[Explanation of symbols]

 1 Axis locking device 2 Internal shaft 3 External shaft 4 Small diameter part (recess)

Claims (3)

[Claims] 1. A shaft lock device comprising an inner shaft and a resin outer shaft integrally molded with the inner shaft. 2. The shaft locking device according to claim 1, wherein the inner shaft has a convex portion or a concave portion inside the outer shaft for preventing movement of the inner shaft in the axial direction with respect to the outer shaft. Alternatively, a shaft locking device characterized in that a combination of these convex portions and concave portions is formed. 3. An internal shaft made of metal and an external shaft made of resin into which the internal shaft is inserted are relatively rotatable while having surface friction resistance, so that these shafts rotate at arbitrary angles,
And a method of manufacturing a shaft lock device that can be fixed, including a step of forming an outer shaft integrated with the inner shaft by disposing the inner shaft inside the resin and performing integral molding. Of manufacturing a shaft locking device.