JPH04262151A - Automatic speed change mechanism utilizing solenoid action at the time of constant current - Google Patents

Abstract

PURPOSE:To provide an automatic spied change mechanism, enabling automatic output change according to a load and utilizing solenoid action, by reducing or increasing the output torque of a tool head part. CONSTITUTION:An automatic speed change mechanism, utilizing solenoid action at the time of constant current, features sliding a cylinder part by utilizing the attraction force of an electromagnetic solenoid actuated when a certain fixed current is reached, in a speed change mechanism which is composed so as to arrange the cylinder part, slidably engaging with an engaging means integratedly formed with an epicyclic retaining plate or an internal gear, in an epicyclic gear reduction mechanism, and to change output rotational frequency by changing an engaging object for the cylinder part and the combination of gears before and after the sliding of the cylinder part.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an automatic transmission mechanism for changing the rotational speed of the output shaft of an electric rotary tool, an electric crimping tool, an automatic screw tightening tool, etc. incorporating a planetary gear transmission mechanism, especially when the current is constant. This invention relates to an automatic transmission mechanism that utilizes solenoid operation.

0002

[Prior art] Electric screwdrivers, electric automatic screw tightening tools, etc. have a simple configuration and incorporate a planetary gear transmission mechanism that allows the input shaft and output shaft to be placed on the same straight line. A transmission mechanism is used that can change the rotation speed of an output shaft such as a bit between high and low speeds by sliding gears (often internal gears) to change the combination of gears.

Conventionally, the combination of gears in a planetary gear transmission mechanism has been changed manually according to the load. For example, JP-A-62-24979 and JP-A-61-9
As disclosed in No. 0812, high or low speeds were set by sliding a "knob" touched from the outer cover within a certain range and manually operating a rotation speed switching lever or a slide lever.

[0004] In electrical installation work where electric wires are laid or replaced on site, hydraulic tools are used to crush or cut crimp terminals for connecting electric wires. A known type of hydraulic tool is one in which a pressure-resistant hose connects a hydraulic pump on the ground and a tool head held by a worker working at a height, such as when laying overhead lines.

Alternatively, hand-held hydraulic tools having a built-in hydraulic pump are also known. This hydraulic tool with a built-in hydraulic pump allows the worker to manually push the operating lever repeatedly, causing the plunger of the hydraulic pump to reciprocate, increasing the oil pressure and driving the tool head, which causes the tool head to press the crimp terminal. Electrical construction work such as crushing and connecting electric wires is carried out.

[0006]

[Problems to be Solved by the Invention] With the above-mentioned conventional hydraulic tools, which have a hydraulic pump installed separately on the ground, the pressure hose gets in the way, making it difficult to work, and it is necessary to change the work location. A separate heavy hydraulic pump had to be moved each time, resulting in extremely poor work efficiency.

On the other hand, hydraulic tools with built-in hydraulic pumps do not get in the way of pressure-resistant hoses, but the pressure required in the tool head to crush crimp terminals, etc. is high, and accordingly, it is difficult to operate the operating lever. Since the force required to do the work is not that small, there was a problem in that the more times the work was done, the more fatigue the worker would experience and the harder the work would be.

To solve this problem, the applicant has devised an electric crimping tool that combines a planetary gear transmission mechanism using a battery and a hydraulic pump driven by the transmission mechanism.

[0009] This electric crimping tool can be used with crimp terminals and sleeves when connecting thin electric wires or a small number of electric wires.
If a small force is required to crush the object, increase the rotation speed (in other words, reduce the output torque) to shorten the work time, and reduce the work time when the load is large, such as when connecting thick electric wires or a large number of electric wires. In such cases, it would be convenient if it were possible to automatically reduce the rotational speed and increase the output torque to draw out the force necessary for the work in question.

The present invention has been made in view of the above problems, and its purpose is that when it is necessary to increase the output, the load on the motor increases, and the motor
As the current flowing through the motor increases, the current is detected, and when the current reaches a certain level, the electromagnetic solenoid is activated and the attraction force operates the speed change means, changing the load from a high speed and low torque state to a low speed and high torque state. An object of the present invention is to provide an automatic transmission mechanism that utilizes solenoid operation based on a constant current that can be automatically changed according to the current.

[0011]

[Means for Solving the Problems] That is, as a means for solving the above-mentioned problems, the present invention provides an automatic transmission mechanism that utilizes solenoid operation under constant current, which is mounted on a planetary holding plate or inside a planetary gear reduction mechanism. A cylindrical part that slidably meshes with the meshing means formed integrally with the gear is arranged,
In a transmission mechanism configured to change the output rotation speed by changing the meshing object of the cylindrical part before and after the sliding of the cylindrical part and changing the combination of gears, the sliding of the cylindrical part is caused to reach a certain constant current. The feature is that it uses the attraction force of an electromagnetic solenoid that is activated when

0012

[Operation] The operation of the automatic transmission mechanism using solenoid operation under constant current according to the above-mentioned means will be explained as follows using the reference numerals in the accompanying drawings.

The change lever 11 held by the link 15 attached to the shaft 64 of the electromagnetic solenoid 63 positions the internal gear 26 in the C direction (see FIG. 1). First of all,
When the switch is turned on and the current is below a certain value, the internal gear 26
is the external gear 23e of the planetary holding plate 23d of the planetary gear transmission mechanism.
The eccentric shaft 5, which is a driven shaft and meshes with the external gear 24e of the planet holding plate 24d, is driven at high rotation and low torque, and a force corresponding to a small load is applied to the tool head portion 4.

Next, when it is necessary to increase the output of the tool head section 4, the load on the motor 20 increases and the current flowing through the motor 20 increases. When the current reaches the electromagnetic solenoid 63, the shaft 64 moves in the direction of arrow Q (see FIG. 4), and the change lever 11 rotates. And the change lever 11
The internal gear 26, which is a sliding gear, moves in the B direction via the pins 12 attached to both ends, and meshes only with the external gear 23e of the planet holding plate 23d.

In this way, the eccentric shaft 5, which is the driven shaft, is driven at low rotation and high torque, and a force corresponding to a large load is applied to the tool head 4.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are side views including a partial axial cross-sectional view of an electric crimping tool incorporating an automatic transmission mechanism utilizing solenoid operation under constant current according to the present invention.

This electric crimping tool with an automatic transmission mechanism is housed in a case 1 shown by a two-dot chain line, and is roughly divided into an automatic transmission mechanism part 2, a hydraulic pump part 3, a tool head part 4, It consists of

First, the automatic transmission mechanism section 2 will be explained.

The automatic transmission mechanism section 2 is a transmission mechanism comprised of a motor 20 driven by a portable battery (not shown), and a sun gear, planetary gear, internal gear, etc. that are rotationally driven by the motor 20. It consists of a mechanism.

That is, the transmission mechanism is connected to the rotating shaft 2 of the motor 20.
0a, a planetary gear 21b meshing with an internal gear 21c fixedly held on the sun gear 21a and the gear case 10, which is a cylindrical part;
A planetary holding plate 21d which is rotatably pivoted to the second stage sun gear 22a and integrally formed with the second stage sun gear 22a at the center on the opposite side; The second stage planetary gear 22 meshes with the internal gear 22c of the second stage.
b, a second-stage planet holding plate 22d to which the second-stage planetary gear 22b is rotatably pivoted and a third-stage sun gear 23a integrally formed in the center on the opposite side; and the third-stage sun The third stage internal gear 2 fixedly held on the gear 23a and the gear case 10
3c meshes with the third stage planetary gear 23b, and the third stage planetary gear 23b is rotatably pivotally connected to the fourth stage internal gear 24.
c and an external gear 23e.
d, internal gear 2 formed on the third stage planet holding plate 23d
4c, the fourth stage planetary gear 24b meshes with the planetary gear 2
4b is rotatably pivoted to form an external gear 24e, and a fourth stage planetary holding plate 24d is spline-connected to the eccentric shaft 5, meshing with the fourth stage planetary gear 24b and connected to the one-way clutch shaft 25. Fitted fourth stage sun gear 24a
, and both the external gear 23e of the third-stage planet holding plate 23d and the external gear 24e of the fourth-stage planet holding plate 24d, or the external gear of the fourth-stage planet holding plate 24d, by a sliding means to be described later. The internal gear 26 meshes only with the gear 24e.

The one-way clutch shaft 25, which has the fourth stage sun gear 24a fitted at one end, is fitted at the other end into the gear case 10 via a one-way clutch 37 so as to rotate in only one direction. It has been done.

Next, the hydraulic pump section 3 will be explained.

In this hydraulic pump section 3, a hydraulic circuit is formed between the oil tank 6 and the tool head 4, and is configured to apply high pressure to the tool head 4.

In the drive mechanism, the eccentric shaft 5 is connected to the fourth stage planet holding plate 24d by spline connection, and the eccentric shaft 5 is connected to the rotating shaft portion 5a and two eccentric shafts having different phases. The portion 5b is formed by the portion 5b. The eccentric shaft 5
is an outer ring 2 with one end fitted into the gear case 10.
7, the other end is fitted into the gear case 10 via a rolling bearing so as to be rotatable. The ends of the cam plungers 51 and 52 are fitted into the two eccentric shaft parts 5b via needle bearings, and the other ends are connected to the first cylinder chamber 31.
and is fitted in the second cylinder chamber 32 so as to be able to reciprocate freely.

That is, due to the rotation of the eccentric shaft 5 and the accompanying reciprocating motion of the cam plungers 51 and 52, oil is transferred from the oil tank 6 to the first cylinder via the check valve 8 and from the first supply path 33. The oil is supplied to the second cylinder chamber 32 from the second supply path 34 to the chamber 31 and via the check valve 8.
sent to. A cylinder chamber 3 formed in the front part of the hydraulic pump section 3 receives high-pressure oil through a check valve 9.
The piston 36 in the tool head 5 is pushed to crush crimp terminals placed on the tool head 4 for connecting electric wires (not shown).

Next, switching of the rotational speed of the drive mechanism in accordance with the load generated in the tool head 4 in order to crush crimp terminals and the like when connecting electric wires and the like will be explained.

FIG. 3 is a sectional view taken along the line A--A in FIG. 1, with internal planetary gears and the like omitted. As mentioned above,
The eccentric shaft 5 of the hydraulic pump section 3 rotates together with the fourth stage planetary holding plate 24d, and in this case, the transmitted rotational torque varies in magnitude by sliding the internal gear 26. In this case, the internal gear 26 has pins 12 and 12 attached to both ends of a change lever 11 disposed straddling the outside of the gear case 10 fitted into a groove 26a provided around the outside of the internal gear 26. Insert the change lever 11
Male screw pins 13 and 13 screwed into gear case 10
(A protrusion may be used instead of the male screw pin 13) as a fulcrum to rotate and slide.

That is, in FIGS. 1 and 2, the internal gear 2
6 is in position C, the internal gear 26 meshes with the external gear 23e of the third-stage planet holding plate 23d and the external gear 24e of the fourth-stage planet holding plate. In this case, the third-stage planet holding plate 23d and the fourth-stage planet holding plate 24d rotate together by the meshing internal gears 26, and are pivotally connected to the fourth-stage planet holding plate 24d. The planetary gear 24b also only revolves integrally with the sun gear 24a with which the planetary gear 24b meshes, and does not perform any deceleration action (in this case,
The direction of rotation of the sun gear 24a is the direction in which the one-way clutch 37 can rotate). Therefore, the fourth stage planet holding plate 24d rotates at high speed, the rotational torque transmitted to the eccentric shaft 5 is small, the hydraulic pressure that can be generated in the hydraulic circuit is also low, and the force generated in the tool head section 4 is small; The piston 36 moves at high speed and the working time is short.

Further, when the internal gear 26 moves in the direction B due to the operation of an electromagnetic solenoid, which will be described later, the internal gear 26 no longer meshes with the external gear 24e of the fourth stage planet holding plate 24d. In this case, the fourth stage sun gear 24a receives a rotational force from the one-way clutch 37 in a direction that prevents rotation, and is stopped from rotating by the one-way clutch 37. A fourth internal gear 24c and a fourth planetary gear 24b, which are integrally formed with the sun gear 24a and the third planetary holding plate 23d, receive input from the internal gear and output from the planetary gear. The fourth stage planet holding plate 24
d rotates at low speed.

Therefore, the eccentric shaft 5 spline-coupled to the fourth stage planet holding plate 24d also rotates at a low speed. Therefore, the rotational torque transmitted to the eccentric shaft 5 is large, the hydraulic pressure generated in the hydraulic circuit becomes high, and a large force is generated on the tool head 4.

Next, the rotation mechanism of the change lever 11 for sliding the internal gear 26 will be explained.

FIG. 4 is a side view of the electric crimping tool shown in FIG. 1 seen from the back side, and FIG. 5 is a view taken along arrow P in FIG.

In these figures, 60 is a motor driven by a battery (not shown), and 61 is a gear reduction mechanism that operates a mechanism (not shown) for returning the hydraulic pressure of the hydraulic pump section 3. A gear case 62 is a valve cam driven by the gear reduction mechanism, and 63 is an electromagnetic solenoid.

A shaft 64 is attached to the electromagnetic solenoid 63 so as to pass through the shaft 64. At the end of the shaft 64, as shown in FIG. It is attached via a spring 16. Further, a step-shaped shaft 64a is formed at the other end of the shaft 64, and a locking portion 17a of the latch 17 formed in an L-shape is attached to the stepped shaft 64a. In this case, the lower part of the latch 17 has a shaft 1
7b is formed, and the shaft 17b is fitted into a hole 65a bored in an L-shaped plate 65 provided at the end of the solenoid 63 via a spring 18 so as to be movable up and down.

Change lever 11 configured as above
In the rotation mechanism, the locking portion 17a of the latch and the shaft 64a of the electromagnetic solenoid are initially disengaged, and the change lever 11 held by the link 15 by the biasing force of the spring 16 moves the internal gear 26 to C. (see FIG. 1).

First, when a switch (not shown) is turned on and the current is below a certain value, the internal gear 26 is moved to the planet holding plate 23.
external gear 23e of d and external gear 24e of planet holding plate 24d
The eccentric shaft 5 is driven at high rotation and low torque, and as described above, a force corresponding to a small load is applied to the tool head 4.

Next, when it is necessary to increase the output of the tool head section 4, the load applied to the motor 20 increases and the current applied to the motor 20 increases. When a certain constant current is reached, the electromagnetic solenoid 63 is activated, the shaft 64 moves in the direction of arrow Q, and the change lever 11 rotates. And the change lever 1
1 through pins 12 attached to both ends of the internal gear 26.
moves in the B direction and meshes only with the external gear 23e of the planet holding plate 23d. In this way, the eccentric shaft 5 is driven at low rotation and high torque, and a force corresponding to a large load is applied to the tool head 4.

In this case, the shaft 6 of the electromagnetic solenoid 63
4a overcomes the biasing force of the spring 18 and pushes the shaft 17b into a state where it is locked with the locking portion 17a of the latch.

Next, when the work at low rotation and high torque is finished and the switch (not shown) for the motor 60 is turned on, the hydraulic pressure in the hydraulic pump section 3 is released by a forced return mechanism (not shown). At this time, the valve cam 62 rotates once through the gear reduction mechanism in the gear case 61 and pushes down the latch 17, and the stepped shaft 64a of the electromagnetic solenoid 63 and the locking portion 17a of the latch 17 are disengaged. The shaft 64 is moved by the biasing force of the spring 16, the change lever 11 is rotated, and the internal gear 26 is moved in the C direction (see FIG. 1). In this way, the automatic transmission mechanism section 2 is placed in a high rotation and low torque state again.

Although the electric crimping tool has been described as a specific example of the present invention, it can be widely used not only in the above example but also in a power transmission mechanism having a planetary gear transmission mechanism that changes the output torque by changing the rotational speed.

[0041]

[Effects of the Invention] The automatic transmission mechanism according to the present invention, which utilizes solenoid operation under constant current, has the structure described in detail above, so that it can be used in portable power tools and electric crimping tools to automatically change speeds. It is possible to perform efficient work by changing the rotational speed (driving torque) and exerting force according to the load.

[Brief explanation of the drawing]

[Figure 1] and

FIG. 2 is a side view including a partial axial cross-sectional view of the electric crimping tool with an automatic transmission mechanism according to the invention.

FIG. 3 is a cross-sectional view taken along the line AA in FIG. 1, with internal planetary gears and the like omitted.

FIG. 4 is a side view of the electric crimping tool of FIG. 1 seen from the back side.

FIG. 5 is a view taken along arrow P in FIG. 4;

[Explanation of symbols]

2 Automatic transmission mechanism section 3 Hydraulic pump section 4 Tool head section 5 Eccentric shaft 6 Oil tank
8, 9 Check valve 10 Gear case 11 Change lever 12 Pin 15 Link 16, 18 Spring
17 Latch 20 Motors 21a, 22a, 23a, 24a Sun gear 21b,
22b, 23b, 24b Planetary gears 21c, 22c,
23c, 24c Internal gears 21d, 22d, 23d,
24d Planetary gear holding plate 25 One-way clutch shaft 26 Internal gear 27 Outer ring 3
1, 32 Cylinder chamber 35 Cylinder chamber 36 Piston 37 One-way clutch 51, 52 Cam plunger 60
Motor 62 Valve cam 63 Electromagnetic solenoid 64 Shaft 65 Plate

Claims (1)

[Claims] Claim 1: A cylindrical part that slidably meshes with a planetary holding plate or a meshing means integrally formed with an internal gear is disposed in a planetary gear reduction mechanism, and the cylindrical part is disposed before and after sliding of the cylindrical part. In a transmission mechanism configured to change the output rotation speed by changing the meshing target and changing the combination of gears, the attraction force of an electromagnetic solenoid that is activated when a certain current is reached is used to move the slide of the cylindrical part. An automatic transmission mechanism that utilizes solenoid operation under constant current.