JPH01274910A - Hammer drill - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an abnormal sound by applying the constitution wherein a clutch is provided with a member movable in a direction orthogonal with the axial direction of a drill bit and the shift of the member is used to turn on and off a connection condition between a motor and a motion conversion member. CONSTITUTION:When the tip of a drill bit 8 is pressed to a drilling surface, a steel ball 61 is pressed inwardly and coupled to the engagement recess part 27 of an intermediate shaft 23. As a result, a cylindrical body 50 retaining the steel ball 61 is connected to the intermediate shaft 23 via the steel ball 61. Thereafter, a piston 4 starts to reciprocate via the motion conversion member 5. Namely, power transmission between the intermediate shaft 23 and the member 5 is turned on and off via the shift of the steel ball 61 in a direction orthogonal with the axial direction of the drill bit 8. According to the aforesaid construction, even if a vibration in an axial direction is transmitted to a clutch disc 65 and the like due to a reaction force at the time of applying a striking impact to the drill bit 8, the connection of the intermediate shaft 23 and the cylindrical body 50 with the steel ball 61 is free from the effect of the vibration and maintained stably, thereby ensuring a freedom from abnormal sound generation.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a hammer drill in which not only rotation but also axial impact impact can be applied to the drill bit.

[Conventional technology]

There is a tool called a hammer drill as a tool for drilling holes in concrete. This includes a striking means that is reciprocated in the axial direction and a striking body that is also slidable in the ring direction, and an air spring is interposed between the two.
The movement of the striking means is transmitted to the striking body through an air spring, and a striking impact is further applied to the drill bit rotationally driven by the striking body. By the way, does trilby also occur when operating the drill bit without pressing it against the surface to be drilled? ), if impact impact is applied to the drill bit (in other words, if dry drilling occurs), damage to various parts will be accelerated.Usually, this type of tool is equipped with a drill bit attached to the surface to be drilled to prevent dry drilling. Although the structure is such that the impacting body does not impact the drill bit when it is not being pressed, the reciprocating drive of the impacting means and the reciprocating movement of the impacting body were still occurring, so damage caused by dry hitting was unlikely. Although it can be prevented, there are problems in that energy consumption is large and noise is generated even though the work is not actually performed. Energy consumption is a big problem, especially in products that use batteries as a power source. This will be the f1 question. To this end, British Published Patent No. 2,170,746 shows the following. This is because a clutch is provided between the striking means and the motor, and when the drill bit is pressed against the surface to be drilled, this clutch is released, and when the drill bit is released from the surface to be drilled, the clutch is disengaged and the striking means is activated. In other words, the spindle, which holds the drill bit and transmits the rotational force from the motor to the drill bit, is made to be able to slide freely in the j direction, and the drill bit is attached to the surface to be drilled. Press 1. The above clutch is connected by utilizing the spindle's retraction when attached, and the impact shock is applied to the drill bit. The striking means for drilling is activated only when the drill bit is pressed against the surface to be drilled.

[Problem to be solved by the invention]

By the way, in hammer drills that are equipped with a clutch that can disconnect the power transmission to the striking means, including the above-mentioned conventional example, the clutch moves the required members in the axial direction of the drill bit, thereby reducing the important power transmission. Because the impact impact during drilling is transmitted to the clutch, this reaction causes the important parts to vibrate slightly in the important direction, making the clutch connection state unstable. This has the problem of generating abnormal noise. In the conventional example described above, since the axial movement of the drill bit is transmitted to the clutch and the clutch performs an important operation, it is even more susceptible to the effects of vibration. The present invention has been made in view of these points, and its purpose is to reduce the reaction of impact impact during drilling.
In addition to maintaining a stable connection even when -/chi is received,
To provide a hammer drill that does not generate abnormal noise.

[Means to solve the problem]

Therefore, the present invention includes a motor, a spindle that is rotationally driven by the motor and holds a drill bit, and a spindle that is connected to the motor via a motion converting member to perform reciprocating motion, and an air spring and a striking body. A striking means that applies a striking impact to the drill bit through the motor, and is located between the motor and the motion conversion member to transmit power between the two! 1181
In the hammer drill, the clutch includes a member that moves in a direction perpendicular to the axial direction of the drill bit, and the movement of this member affects the connection between the motor and the motion converting member. vt to be something
It has signs. E-action] According to the present invention, even if the reaction of the impact impact on the drill bit is transmitted to the clutch, the important member in the clutch moves in the direction perpendicular to the axial direction of the drill bit, thereby maintaining the connected state. Since the drill bit is designed to carry out important operations, it is not affected by the reaction of a strike against the drill bit, that is, by vibration in the axial direction of the drill bit. [Examples] The present invention will be described in detail below based on illustrated examples. First, to explain the overall structure, the main body housing 1 has a chuck part 13 on its front end to which the drill bit 8 is attached, a handle part 1G extending from the lower part of the rear end, and a handle part 1G extending from the lower part of the rear end. On the other hand, a storage battery bag 9 is detachably attached to a position on the front side of the handle part i6. In the figure, 14 is a switch handle, and 15 is a rotation direction switching handle. The motor 2 is housed in the rear part of the main body housing 1 with its axial direction being the front-back direction, and a pinion 21 is fixed to the output shaft 20 of the motor 2, as shown in FIG. The gear 24 that the binion 21 meshes with has both ends connected to the housing 11 and the motor mounting base 12, and the wheel receivers 22, 22 are connected to each other.
The intermediate shaft 23 is press-fitted and fixed to one end of the intermediate shaft 23, which is rotatably supported through the intermediate shaft 23, so that the axial direction is parallel to the axial direction of the motor 2. It is press-fitted and fixed to one end of 1123. The intermediate shaft 23 has a motion converting member 5 attached to the gear 2411m, and a binion 25 is formed on the outer circumferential surface of the other end, and a clutch 6, which will be described later, is provided on the outer circumference between the binion 25 and the motion converting member 5. is installed. Inside the front end of the main body housing 1, which also serves as a gear case, is a spindle 3 rotatably supported by a bearing 30.
has been set up. This spindle 3 has a gear 32 that meshes with the pinion 25 fixed to the outer circumferential surface of the rear layer part with a key 38 and a retaining ring 39, and a striker 33 is disposed inside so as to be slidable in the axial direction. The tip is a chuck that holds the drill bit 8 so that it can slide freely within a predetermined range! It constitutes one part of 3. Here, the striker 33 has its sliding range in the axial direction restricted by a locking body 34 fixed inside the spindle 3, and the rear end portion having a small diameter has a locking body 34 fixed inside the spindle 3. A cup-shaped clutch bushing 35 housed in the end portion is covered, and an elastic body 37 such as an 017 ring is disposed so that the elastic body 37 is axially spaced between the spindle 3 and the clutch bushing 35. positioned. The clutch bushing 35 has a protrusion 36 projecting from the rear end opening of the spindle 3. On the other hand, at the rear of the striker squid 33, there is a piston 4 in the shape of a cylinder with a bottom as a striking means. A sliding impact body 41 is installed in the piston 4. The piston 4 is connected to the intermediate shaft 23 and spindle The rear end side connected to the motion converting member 5 is closed.The motion converting member 5 converts rotational motion into reciprocating motion. A cylinder 50 into which the intermediate shaft 23 is inserted, a ring 52 freely attached to the outer peripheral surface of the cylinder 50 via a number of balls 51, and a ring 52 protruding from the ring 52. axis 5
3, a universal joint 54 into which a sleeve 53 is slidably inserted, and whose spherical outer surface is rotatably connected to the rear end of the piston 4 via a joint receiver 55; 53 to urge the universal joint 54 toward the joint receiver 55. It is located in a long groove 42 extending in the axial direction of the piston 4. Since the rotation center axis of the ring 52 in the motion converting member 5 is inclined with respect to the axial direction of the intermediate shaft 23, when the cylinder body 50 rotates together with the intermediate shaft 23, the ring 52 protrudes from the ring 52. The provided shaft 53 swings within a plane that includes both sleeves of the piston 4 and the intermediate shaft 23 because the rotation of the intermediate shaft 23 rotation 9 is restricted from the piston 4 side. As a result, the piston 4 is driven back and forth. Next, a description will be given of the clutch 6 that turns on/off transmission of rotation between the cylinder body 50 of the motion converting member 5, which is freely rotatable with respect to the intermediate shaft 23, and the intermediate shaft 23. This clutch 6 includes a cylindrical clutch shaft 60 disposed on the outer periphery of a portion of the intermediate shaft 23 between the binion 25 and the motion conversion member 5, and a clutch plate 65 disposed on the outer periphery of the clutch shaft 60. and the cylindrical body 50 of the motion converting member 5 is connected to the intermediate shaft 23.
The steel ball 61 is connected to the steel ball 61. The clutch shaft 61 is slidable in the axial direction with respect to the intermediate shaft 23, and a thrust plate 62 and a spring receiver 63 are attached to the vinyl on 25 side, and the other end is attached to the outer periphery. A protrusion 64 is formed on the surface, and the intermediate shaft 2
It is biased toward the pinion 25@ by a return spring 75 disposed between it and the retaining ring 26 attached to the pinion 3. The clutch plate 65 is further slidable in the axial direction with respect to the clutch shaft 61, and the clutch plate 65 is slidable in the axial direction with respect to the clutch shaft 61.
A protrusion 66 that engages with the cylindrical body 50 is provided on the inner circumferential surface of one end, a 7-hole 67 is provided on the outer circumferential surface, and a retraction portion 68 with a larger inner diameter is provided on the inner circumferential surface of the other end, which is the side of the cylinder 50. and the pressure spring 76 disposed between the spring receiver 63 and the spring receiver 63.
It is biased toward the motion conversion member 5gJA. The steel balls 61 are respectively disposed in a plurality of holding holes 57 formed at the ends of the target body 50 located between the inner surface of the clutch plate 65 and the intermediate shaft 23, and each of the steel balls 61 has a diameter of The wall thickness is larger than that of the cylindrical body at the 50-inch end. The outer circumferential surface of the intermediate shaft 23 has an engagement l! with which the steel ball 61 engages when the steel ball 61 moves toward the center of the cylindrical body 50 by being pushed by the clutch plate 65. A plurality of portions 27 are provided. However, in the lever hammer drill, when the tip of the drill bit 8 is not in contact with the surface to be drilled, the striker 33 is in an advanced position as shown in FIG. Also, at this time, the clutch pongee 60 and the ri-7 due to the return bone 75? The large retraction portion 6 of the inner diameter of the clutch plate 65 is biased by the clutch plate 65.
8 is located on the outer periphery of the steel ball 61, and the steel ball 61 is allowed to retreat to the retreat portion 68, so that the intermediate shaft 23 and the cylindrical body 50 are in a cut state. Therefore,
When the motor 2 is operated by operating the switch handle 14, the rotation of the motor 2 is transmitted from the intermediate shaft 23 to the drill bit 8 via the spindle 3, but since the motion conversion member 5 is separated, The piston 4 does not reciprocate (the drill bit 8 only rotates. In this state, if the tip of the drill bit 8 is pressed against the surface to be drilled, the result will be as shown in Fig. 2). , the drill bit 8 is retracted 1 with respect to the spindle 3 within the permitted range.
1. Push the striker 33 backward to make it retreat. The stob buoy force 33 moves the elastic body 37 and the clutch bushing 35 rearward, and the protrusion 36 of the clutch bushing 35 pushes against the thrust plate 62 and the spring receiver 6.
3, the clutch pongee 60 is pushed toward the motion conversion member 5 against the return spring 75. As a result, the clutch plate 65 is biased by the pressure spring 76! ! ! The steel ball 61 moves toward the motion converting member 5 side, and in order to position the portion with an inner diameter smaller than the retracted portion 68 on the outer periphery of the steel ball 61, the steel ball 61 is pushed inward and engaged with the intermediate shaft 23. It engages with the fourth part 27. The cylinder 50 holding the steel ball 61 is connected to the intermediate shaft 23 via the steel ball 61. For this reason, from now on, the piston 4 reciprocates through the motion converting member 5, and the striking body 41 follows the reciprocating motion of the piston 4 via the air spring between the inner bottom surface of the piston 4 and the striking body 41 (- 1, and the impact impact when the striking body 41 strikes the striker 33 is transmitted to the drill bit 8 through the striker 33. Here, the importance of the power transmission between the intermediate shaft 23 and the motion converting member 5 is that the drill bit Since the steel ball 61 moves in a direction perpendicular to the axial direction of the drill bit 8, even if the vibration in the wheel direction due to the reaction when applying a blow to the drill bit 8 is transmitted to the clutch plate 65, etc. The connection between the intermediate shaft 23 and the cylindrical body 50 by the W4 ball 61 is maintained in a stable state without being affected by this vibration.
Furthermore, in this embodiment, the striker 33 and the clutch bush 35 do not generate any abnormal noise.
Since the elastic body 37 disposed between the clutch plate 65 and the pressing spring 76 absorb vibrations, the vibration itself transmitted to the clutch plate 65 and steel balls 61 side is reduced. When the drilling work is completed and the drill bit 8 is released from the surface to be drilled, the clutch pongee 607>f is biased by the return spring 75.
When the steel ball 61 returns to its original position, the clutch plate 65 is also pulled by the clutch pongee 60 and separated from the motion conversion member 5, and the steel ball 61 is retracted to the retraction portion 68 in order to position the retraction portion 68 on the outer periphery of the steel ball 61. Then, the clutch 6 is disengaged. Also clutch bush 35, striker 33 and Zodryl bit 8
The state also returns to the state shown in FIG. Therefore, the drill bit 8 is in a state where it only rotates. When drilling into iron plates or wood does not need to be accompanied by a blow, as in the case of work, it is only necessary to operate the release lever 70 provided on the side of the main body housing 1, as shown in Fig. 4 and Fig. 11%5. A detachment lever 70 rotatably attached to the housing 1 has a pin 71 protruding from an eccentric position on its tip surface, and a pin 71 protrudes from an eccentric position on the tip surface,
A roller 72 that is in contact with the surface of the flange 67 on the motion conversion member 5 side is supported by a pin 71 so as to be freely rotatable.
When the separation lever 70 is rotated, as shown in FIG. 3, the roller 72 comes into contact with the 7-run no. 67, thereby preventing the clutch plate 65 from moving toward the motion conversion member 5. For this reason, as shown in the figure, even when the clutch bush 35 pushes the clutch shaft 61, the clutch 6
Forcibly prevent entry.

【Effect of the invention】

As described above, in the present invention, the clutch includes a member that moves in a direction perpendicular to the axial direction of the drill bit, and the movement of this member maintains the connection between the motor and the motion converting member. Even if the vibration caused by the reaction of the impact impact on the drill bit is transmitted to the clutch, the clutch member is not connected properly because the direction in which the clutch is activated and the direction of vibration are different. is not affected by vibration, maintains a stable connection state, and does not generate abnormal noise.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of one embodiment of the present invention, Fig. 2 is a longitudinal sectional view of the same when the same clutch is connected, Fig. 3 is a longitudinal sectional view when the same as the above clutch is forcibly disengaged, and Fig. 4 is a longitudinal sectional view of the same as the above when the clutch is forcibly disengaged. Broken side view,
FIG. 15 is a cross-sectional view of the same as above, and 2 is a motor, 3 is a spindle, 4 is a piston, 5 is a motion conversion member, 6 is a clutch, 8 is a drill bit, 41 is a striking body, 60 is a clutch shaft, 61 indicates a steel ball, and 65 indicates a clutch plate. Agent Patent Attorney Ishi 1) Ai Shichi

Claims (1)

[Claims] (1) A motor, a spindle that is rotationally driven by the motor and holds the drill bit, and a spindle that is connected to the motor via a motion conversion member to perform reciprocating motion and that is connected to the drill bit via an air spring and a striking body. In a hammer drill equipped with a striking means that applies a striking impact and a clutch located between a motor and a motion converting member to control power transmission between the two, the clutch is arranged in a direction perpendicular to the axial direction of the drill bit. A hammer drill comprising a movable member, and the movement of this member connects and disconnects the motor and the motion converting member.