JPH027089B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a grip with a push button switch that is attached to the upper part of an operating lever of a construction machine or the like.

[Conventional technology]

BACKGROUND OF THE INVENTION When operating construction machinery such as hydraulic excavators, bulldozers, and truck cranes, it is necessary to issue a warning to people around the machinery for safety reasons. The alarm push button switch is usually attached to the grip of the operating lever because if it can be activated without taking your hand off the operating lever, you can immediately issue an alarm when you sense danger.

A conventional grip with a push button switch for an operating lever of a construction machine is disclosed in Japanese Utility Model Publication No. 48-8082. The main body of this grip consists of an insulator provided at the upper end of a tubular conductive lever, with a conductive cylinder fitted into a vertical hole in the center, and a conductive cylinder fitted into the inner cylinder at the upper end. A switch button is provided through an insulating cover that covers the upper part of the body and an insulating cylindrical body, and this switch button is biased upward via a spring between it and a conductive ring screwed onto the middle part of the conductive cylindrical body. There is. The upper part of the electrically conductive tubular lever is screwed onto the lower part of the electrically conductive cylinder, and a contact is provided between the upper end of the lever and the electrically conductive ring through an insulator, facing the switch button. The lead wire passes through the lever tube and is connected to the anode of the power source via the horn. Also, the conductive lever is connected to a cathode of a power source. Then, when the operator presses down the switch button while holding the grip of the lever, the switch button contacts the contact point, and the current from the power source passes through the switch button and spring from the lead wire, and from the conductive cylinder to the lever. The warning horn sounds.

Further, there is an example of a grip with a push button switch attached to the upper end of the operating lever as in the prior art, as shown in FIGS. 5 and 6, which will be described below.

A screw hole 1a is provided at the bottom of the grip body 1, which is formed of a hard material (for example, an insulator such as wood or synthetic resin) into a roughly spherical shape that can be held in the hand. It is fitted into a threaded rod 100a provided at the upper end of the.
A push button switch 2 is attached to the central upper end of the grip body 1. The case 2a of the push button switch 2 is housed in a recess provided at the upper center of the grip body 1, and inside the case 2a,
A push button 2b made of an insulating material with a contact plate 2c made of an electrical conductor provided at the lower end, and positive and negative contact terminals 2f, 2.
The insulating plate 2e to which g is attached, the spring receiving part of the push button 2b, and the spring 2d interposed between the insulating plates 2e are housed. A lead wire 3 is suspended from each of the contact terminals 2f and 2g, and the lead wire 3 is led out through a hole provided in the operating lever 100. Each lead wire 3 is connected to one and the other of both poles of the power source.

Push button 2b to connect contact plate 2c to contact terminal 2f,
2g, both contact terminals 2f and 2g are short-circuited and an electric circuit is closed. When the push button 2b is released, the push button 2b is pushed up by the spring 2d and the electric circuit is opened.

[Problem that the invention seeks to solve]

By the way, the grip for the operating lever disclosed in Publication of Utility Model Publication No. 48-8082 is electrically conductive, so touching the lever with wet hands when it is exposed to rain water may cause an electric shock, which is dangerous. In addition, the cover covering the top of the conductive cylinder is easily removed or broken, allowing dust and rainwater to enter the inside of the push button.
This may cause poor contact, poor insulation, or electric shock. Furthermore, water may enter between the cover and the conductive cylinder, causing problems similar to those described above.

In the conventional grip shown in FIGS. 5 and 6, the two lead wires 3 connected to both poles of the power supply pass through the hole in the operating lever 100, so there is no need to make the operating lever conductive. Unlike Publication No. 48-8082, there is no risk of electric shock from directly touching the operating lever. However, when the push button 2b is pushed down, a gap C is created between the upper end of the case 2a and the push button 2b, and dust enters the inside of the case 2a from the gap C and adheres to the contact plate 2c and the contact terminals 2f and 2g. death,
Even if the contact plate 2c is brought into contact with the contact terminals 2f and 2g, the contact will be poor due to the attached dust, and the function of the switch will deteriorate. Further, when rainwater is applied, water may enter from the gap C, causing insulation failure and causing electric shock, and other similar problems may occur.

In order to deal with the above problems, the Jiko Kosho 55
Publication No. 39464 discloses a grip in which the entire grip body and an electric switch provided inside the grip are covered with a spherical bag made of a flexible material such as rubber. After the grip is manufactured, the bag is covered by elastic deformation, and the bag must necessarily be made thin, easily torn, and lacking in durability, making it impractical.
Furthermore, this grip is of a type that turns on an electric switch by squeezing it, and its purpose is different from that of a push button switch, which is operated separately from a lever operation.

Note that Japanese Utility Model Publication No. 56-29219 discloses an injection molding method for covering the surface of the operating lever grip body with a flexible synthetic resin material, but this method does not prevent rainwater from entering the inside of the push button. It does not cover the entire grip body and pushbutton to completely prevent intrusion, nor does it use any ingenuity to make the grip easy and inexpensive to manufacture and not impair the operating feel of the pushbutton switch. It is merely indicated that injection molding is used.

This invention prevents the occurrence of contact failure, poor insulation, and electric shock at switch contacts, and easily and inexpensively manufactures a durable grip with a push button switch for an operation lever, without impairing the operational feeling of a conventional push button switch. The purpose is to

[Means for solving problems]

In order to achieve the above object, the method for manufacturing a grip with a push button switch of the present invention is such that the grip main body of the grip attached to the upper end of the operating lever is connected to a grip core having a partially spherical outer circumferential surface and a cylindrical hollow portion. and a grip shaft to be fitted into the cylindrical hollow part of the grip core,
a step of attaching a push button switch to the upper end of the grip shaft, and inserting into the grip core a core metal having approximately the same shape as the grip shaft and having a spherical upper end outer peripheral surface with its upper end protruding. process and
A process of injection molding a flexible polymer material on the outer peripheral surface of the grip core and the core metal to form a skin that covers the grip core and the core metal, and then extracting the core metal and removing the empty grip core. The grip shaft having a push button switch attached to the upper end thereof is inserted into the hollow hole of the grip shaft, and the upper end of the push button switch is brought into contact with the upper inner wall surface of the skin.

[Effect]

The grip body is manufactured separately into a grip core body and a grip shaft, and a core metal having approximately the same shape as the grip shaft and having a spherical outer circumferential surface at the upper end is inserted into the grip core body, and the grip core body and core metal are assembled. After forming a strong skin by injection molding a highly flexible molecular material on the outer circumferential surface, the core metal is extracted, and the grip shaft with the push button switch attached is inserted into the hollow hole, and the upper end of the push button switch is inserted. Contact the upper inner wall of the epidermis.
The grip body and the push button switch are completely covered with the skin, and when the push button switch is pressed down, the upper end of the push button switch is in contact with the inner wall surface of the skin, so the push button switch can be operated without impairing the conventional operating feeling. Ru.

〔Example〕

Next, an embodiment of a grip with a push button switch manufactured by the manufacturing method of the present invention will be described with reference to FIGS. 1 to 3. In these figures, the same reference numerals as in FIGS. 5 and 6 represent the same or equivalent components.

A threaded hole 12a of the grip shaft 12 is fitted into the threaded rod portion 100a of the operating lever 100, and a grip whose outer peripheral surface is partly spherical is formed on the outer periphery of the upper part of the grip shaft 12. A core 11 is fitted, and the grip core 11 and the grip shaft 12 form a grip body. A push button switch 2 is fitted inside the upper end of the grip shaft 12. The grip core 11, the lower part of the grip shaft 12, and the push button switch 2 are covered with a grip skin 10 made of a flexible polymeric material, such as a soft synthetic resin. A plurality of, e.g. three, protrusions 10a formed vertically at intervals on the inner circumferential surface of the grip skin 10 are fitted into vertical grooves 11a formed on the outer circumferential surface of the grip core 11, respectively.

Since the protrusion 10a of the grip skin 10 fits into the vertical groove 11a of the grip core 11,
When the grip is screwed onto the threaded rod 100a of the operating lever 100, the grip can be fastened without the grip skin 10 twisting.

Note that the upper end surface of the push button switch 2 is formed into a spherical shape along the spherical surface of the upper inner wall of the grip skin 10, so even if there is a deviation in the push button operation position and direction from the grip skin 10, the push button switch 2 will not operate. A movement movement is performed precisely along the axial direction of the grip shaft 12.

Such a grip is manufactured by the following process. That is, first, the grip body is manufactured separately from a grip core 11 having a spherical outer peripheral surface and a cylindrical hollow portion, and a grip shaft 12 which is later fitted into the cylindrical hollow portion of the grip core 11. Then, a push button switch 2 equipped with a push button 2b, a contact plate 2c, a spring 2d, an insulating plate 2e, contact terminals 2f, 2g, a lead wire 3, etc. is fitted inside the upper end of the grip shaft 12. Next, as shown in FIG. 4, a core bar 120 having substantially the same shape as the grip shaft 12 and having a spherical upper end outer peripheral surface is inserted into the grip core body 11 with its upper end protruding. Next, in this state, the grip core 11 and the core metal 12 are
A flexible polymeric material such as a soft synthetic resin is injection molded onto the outer peripheral surface of the grip 0 to form a grip skin 10 that covers the grip core 11 and the metal core 120. Next, only the core bar 120 is removed from the grip skin 10 and the grip core 11, and the grip shaft 12 with the push button switch 2 fitted to the upper end is inserted into the hollow hole of the grip core 11. The upper end portion is brought into contact with the upper inner wall surface of the grip skin 10.

When the grip core 11 and the grip shaft 12 are made into an integral body and the grip skin is formed by injection molding with the push button switch 2 embedded in the integral body, the push button 2b of the push button switch 2 is pressed by the injection pressure. There is a problem in that the contact plate 2c comes into contact with the contact terminals 2f and 2g, and the switch function is lost. Therefore, when forming the grip skin 10 by separating the grip core 11 and the grip shaft 12, the core metal 120 is fitted into the hole of the grip core 11, and a soft synthetic resin is injection molded around it. do.

In addition, in the above manufacturing process, the grip shaft 12
Even after the grip skin 10 is formed, the process of fitting the push button switch to the grip skin 10 produces the same effect.

〔Effect of the invention〕

According to the invention described above, the following effects can be obtained.

(1) The push-button switch and the entire grip body are covered with a grip skin formed by injection molding of a polymeric material such as flexible soft synthetic resin, preventing dust and water from entering the switch and preventing the switch contacts from entering. It can prevent poor contact and poor insulation, and completely prevent dangers such as electric shock.

(2) Since the grip skin is formed by injection molding of a polymeric material, the skin can be made durable and unbreakable.

(3) Separately manufacture the grip body into a grip core body having a partially spherical outer peripheral surface and a cylindrical hollow part, and a grip shaft which is later inserted into the cylindrical hollow part of the grip core body 11, A core bar having approximately the same shape as the grip shaft and having a spherical outer circumferential surface at the upper end is inserted into the grip core body, a polymeric material is injection molded on the outer circumferential surface of the grip core body and the core bar to form a grip skin, and the core Since we adopted a process of inserting the grip shaft with the push button switch into the hollow part after removing the gold, the grip with the push button switch has uniform dimensions, can be manufactured easily and inexpensively, and has the push button switch function. Works reliably.

(4) By inserting the grip shaft into which the push-button switch is fitted into the hollow hole of the grip core, and by bringing the upper end of the push-button switch into contact with the upper inner wall surface of the grip skin, the grip shaft does not have a grip skin. The push button can be operated with the same operating feel as a grip with a push button switch.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an example of a grip with a push button switch manufactured by the manufacturing method of the present invention;
Fig. 2 is a cross-sectional side view showing the push button switch in the grip shown in Fig. 1 in a closed state, Fig. 3 is a - sectional view of Fig. 1, and Fig. 4 shows a state where the grip skin in Fig. 1 has been injection molded. FIG. 5 is a cross-sectional side view showing a conventional grip with a push button switch, and FIG. 6 is a cross-sectional side view showing the grip shown in FIG. 5 with the push button switch closed. 1...grip body, 2...push button switch, 10...
Grip skin, 11... Grip core body, 12... Grip shaft, 100... Operating lever, 120... Core metal.

Claims (1)

[Claims] 1. The grip main body of the grip to which the upper end of the operating lever is attached is made up of a grip core body whose outer peripheral surface is partially spherical and has a cylindrical hollow part, and a grip shaft that is inserted into the cylindrical hollow part of the grip core body. a step of manufacturing the push button switch at the upper end of the grip shaft; and a step of attaching the push button switch to the upper end of the grip shaft, and adding a core metal to the grip core that has approximately the same shape as the grip shaft and has a spherical outer peripheral surface at the upper end. a step of inserting the grip core with its upper end protruding; a step of injection molding a flexible polymer material on the outer peripheral surface of the grip core and the core metal to form a skin covering the grip core and the core metal; the step of extracting the core metal, inserting the grip shaft with the push button switch attached to the upper end into the hollow hole of the vacant grip core, and bringing the upper end of the push button switch into contact with the upper inner wall surface of the skin. A method for manufacturing a grip with a push button switch.