JPH0215348B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to impact tools such as battery-powered vibration drills, hammer drills, and rock drilling machines.

[Background technology]

Since conventional vibrating drills cannot be used without a commercial AC power source, we developed a battery-powered vibrating drill as shown in Figure 1. In the figure, 60 is a main body housing, which houses a motor 61 at the rear and has an output shaft 63 at its tip to which a drill bit 62 is attached. The output shaft 63 is given rotation and reciprocating motion by the drive of the motor 61 by a mechanism provided within the main body housing 60 . A battery 64 is housed at the rear of the main body housing 60, and a handle 65 is provided. The battery 64 is connected to the motor 61 via a terminal contact fitting 65.

However, since the terminal contact fitting 65 faces in the reciprocating direction of the output shaft 62 and is in contact with the terminal 64a of the battery 64, vibration during drilling may cause the battery terminal 64a and the terminal contact fitting 65 to separate or come into contact with each other. There was a problem in that the contact state of the battery 64 became unstable due to the force acting thereon. Even if the terminal contact fitting 65 has spring properties, when force is applied in the direction of separation due to vibration, the spring pressure decreases and the contact state becomes unstable. In addition, when the terminal contact fitting 65 has spring properties, a large bending stress acts on the terminal contact fitting 65 when a force is applied in the pressure welding direction, resulting in damage to the terminal contact fitting 65 or shortening of life (large stress (Decrease in repeated bending life due to
It may cause Further, since the terminal contact fitting 65 exceeds the allowable bending load, it is plastically deformed and its elasticity is reduced, making it impossible to obtain a predetermined spring pressure.

Similar problems occur with impact tools other than vibration drills, such as hammer drills and rock drilling machines.

[Purpose of the invention]

An object of the present invention is to provide an impact tool with stable battery contact.

[Disclosure of the invention]

The present invention provides an impact tool in which a mechanism for rotating and reciprocating an output shaft and a battery as a power source for this mechanism are provided in a main body housing, in which the contact direction between a terminal contact fitting attached to the main body housing and a terminal of the battery is controlled. , the direction is perpendicular to the reciprocating direction of the output shaft, and the direction of contact between the battery terminal and the terminal contact fitting is perpendicular to the vibration direction of the battery due to the reciprocating movement of the output shaft. A stable contact condition can be obtained.

Embodiment An embodiment in which the present invention is applied to a vibrating drill is shown in FIGS. 2 to 4. In the figure, reference numeral 1 denotes a main body housing, which includes a cylindrical portion 1a, a grip 2 extending from the rear end of the cylindrical portion 1a, and a battery accommodating portion 3 protruding downward from the rear end of the cylindrical portion 1a. A motor 4 is housed at the rear end of the cylindrical portion 1a, and a drill bit 50 is housed at the front end.
An output shaft 6 to which the motor 4 is attached is provided concentrically with the output shaft of the motor 4. A rotation transmission mechanism and a striking mechanism that cause the output shaft 6 to reciprocate and rotate due to the rotation of the motor 4 are housed in the middle of the cylindrical portion 1a. The output shaft 6 is supported by a bearing 11 and a thrust bearing 21.

The battery 48 is housed horizontally. That is, the longitudinal direction of the battery 48 is aligned with the reciprocating direction of the output shaft 6. Reference numeral 51 denotes a pair of terminal contact fittings provided in the battery accommodating portion 3, which are made of leaf springs. The terminal contact fitting 51 is oriented so as to come into elastic contact with the terminal 48a of the battery 48 in a direction perpendicular to the reciprocating direction of the output shaft 6. The terminal contact fitting 51 is brought into contact with the motor 4 through a lead wire 52, and a switch 53 is interposed in the middle thereof. The battery housing part 3 is provided with a battery fixing cover 55 that opens forward around the support shaft 54, and anti-vibration rubber covering part of the battery 48 is provided on the inner surface of the battery fixing cover 55 and the opposing inner wall of the battery housing part 3. 5
6,57 are provided. Note that the battery 48 is formed by stacking cells, and the stacking direction is set as the reciprocating direction of the output shaft 6.

The rotation transmission mechanism will be explained. A deceleration shaft 7 is provided parallel to the axis on which the output shaft 6 is arranged. The reduction shaft 7 is supported by a bearing 13 and a metal bearing 14 at both ends, and a first reduction gear 15 and a pinion 16 are provided at both ends. First reduction gear 1
5 is fixed to the rotating shaft 4a of the motor 4 and meshes with the pinion 17. The pinion 16 at the tip of the reduction shaft 7 is attached to a gear fixing ring 18 on the outer periphery of the output shaft 6.
It meshes with a second reduction gear 19 fixed to. The gear fixing ring 18 is engaged with a spline groove 20 of the output shaft 6. A bearing 13 at one end of the reducer 7 is provided on a motor fixing base 22 . The motor fixing base 22 is attached to the housing 1 with bolts and nuts 2.
It is fixed with screws to the clamp bearing stand 24 fixed at 3.

The striking mechanism will be explained. A guide cylinder 25 is fixed to the motor fixing base 22, a hammer 5 is fitted into the guide cylinder 25 so as to be movable in the axial direction, and a driver 27 at one end of a forward/backward shaft 26 is accommodated. 28 is a cylinder cap. The hammer 5 has a recess into which the rear end of the output shaft 6 is fitted so as to be movable in the axial direction. The hammer 5, the driver 27 and the spring 29
Connect with. The forward and backward shaft 26 is supported by a metal bearing 31 within the motor fixing base 22 so as to be freely forward and backward. The forward and backward shaft 26 is connected to a drive ring 32, and the drive ring 32 has a long hole through which an eccentric pin 33 passes. This elongated hole extends long in a direction perpendicular to the forward/backward axis 26. The eccentric pin 33 has a roller 3 on its outer periphery.
It has 4. The eccentric pin 33 has a pair of eccentric shafts 35,
It is fixed at 36. Eccentric shafts 35, 36
is supported by the motor fixing base 22 by bearings 37 and 38. A bevel gear 39 is fixed to one eccentric shaft 36, and rotation is transmitted from the deceleration shaft 7 via a bevel gear 40 that meshes with the bevel gear 39.

8 is a switching mechanism. The switching mechanism 8 switches the bevel gear 40 to the bevel gear 3 by sliding the switching operation piece 45.
9 to switch the operation of the output shaft 6 between a rotary impact operation and a rotation-only operation.

The chuck 10 has a hollow shaft 43 into which the proximal end of the drill bit 50 is inserted, and a bit attachment/detachment ball 46.

Operation The rotation of the motor 4 is transmitted to the output shaft 6 via the deceleration shaft 7.
It is then passed on to Drill Bit.
Further, the rotation of the motor 4 is controlled from the deceleration shaft 7 to the bevel gear 3.
9 and 40, and is converted into a forward and backward movement of the forward and backward shaft 26 by the eccentric pin 33. The forward and backward movements of the forward and backward shaft 26 are transmitted to the hammer 5 via a driver 27 and a spring 29. The hammer 5 thereby reciprocates at a predetermined frequency and collides with the output shaft 6. Due to this collision, the output shaft 6 hits the drill bit 50 and applies an impact force to the drill bit 50. In this manner, the drill bit 50 is caused to undergo rotational and oscillating motion.

When drilling, the main body housing 1 holds the drill bit 50.
It vibrates in the direction of arrow A as a result of the impact reaction force. However, the battery terminal 48a and the terminal contact fitting 51
Since the direction of elastic contact with the vibration direction is perpendicular to the direction of vibration,
Even if the battery 48 vibrates in the A direction, the terminal contact fitting 5
The battery terminal 4 remains in the bent state of 1, that is, the bending stress occurring in the terminal contact fitting 51 remains unchanged.
8a and the terminal contact fitting 51 simply slide.
Therefore, even if the terminal contact fitting 51 is made of a spring body, the contact pressure does not change, and a stable contact state of the battery 48 can be obtained. Terminal contact fitting 5
The same applies even if 1 is made of a spring body.

Further, since the battery 48 is elongated horizontally, the center of gravity G of the entire drill is closer to the axis of the drill bit 50 (ie, the line of action L of the impact force) than when the battery 48 is elongated vertically as in the example shown in FIG. Therefore, as shown in FIG. 5, the moment M=F'l of the force from the drill to the human hand due to the reaction force F' of the impact force F becomes small. Therefore, the force required by a person to hold the drill during drilling is small, making it easier to use. In addition, for drills that do not use batteries, such as AC power type,
The center of gravity of the entire drill is placed on the axis of the drill bit, and the reaction force during drilling is received by the entire weight of the drill, so that only a small amount of human holding force is required. but,
In battery-powered drills, the battery must be placed around the main body housing in order to shorten the overall length of the drill and improve ease of use and portability. When arranged in this manner, in this embodiment, the battery 48 is made horizontally long so that the holding force is as small as possible. That is,
This solves both the problem of shortening the overall length and the location of the center of gravity.

Furthermore, vibration isolating rubbers 56 and 57 are arranged on the side surfaces of the battery 48 in the vibration direction of the output shaft 50, which dampen the vibrations of the battery 48. Therefore, the relative sliding between the battery terminal 48a and the terminal contact fitting 51 is reduced, and a more stable contact state of the battery 48 can be obtained.

〔Effect of the invention〕

In the impact tool of the present invention, the contact direction between the terminal contact fitting attached to the main body housing and the battery terminal is perpendicular to the reciprocating direction of the output shaft. Even if the battery vibrates in this reciprocating direction, the contact direction is perpendicular to the vibration direction, and a stable contact state can be obtained.

[Brief explanation of drawings]

Fig. 1 is a broken side view of a conventional example, Fig. 2 is a longitudinal sectional side view of an embodiment of the present invention, Fig. 3 is a front view thereof, Fig. 4 is a sectional view taken along the - line of Fig. 2, and Fig. 5 is also an explanatory diagram of the operation. 1...Body housing, 2...Handle, 3...
...Battery compartment, 4...Motor, 5...Hammer, 6
... Output shaft, 48 ... Battery, 48a ... Battery terminal, 50 ... Drill bit, 51 ... Terminal contact fitting, 56, 57 ... Vibration-proof rubber.

Claims (1)

[Scope of Claims] 1. A main body housing provided with a mechanism for rotating and reciprocating the output shaft and a battery that serves as a power source for this mechanism;
An impact tool comprising: a terminal contact fitting attached to the main body housing so as to face and contact the terminal of the battery in a direction perpendicular to the reciprocating direction of the output shaft. 2. The impact tool according to claim 1, wherein the battery is mounted on the main body housing with its longitudinal direction parallel to the reciprocating direction of the output shaft. 3. The impact tool according to claim 1, wherein a side surface of the battery in the reciprocating direction of the output shaft is covered with vibration-proof rubber. 4. The impact tool according to claim 1, wherein the stacking direction of the cells of the battery is perpendicular to the reciprocating direction of the output shaft.