JPH04269177A - Ratchet wrench - Google Patents

Abstract

PURPOSE:To make the output for driving in a small output with a mechanism load being drastically reduced. CONSTITUTION:A 1st claw 15 freely engageable/releasable with a tooth 18 formed at the inner peripheral part of a driving ring 8 by being pivotally supported on an output shaft 12 is equipped. A tooth 19 formed at the inner peripheral part of a main body case 1 by being pivotally supported on the output shaft 12 and a freely engageable/separatable 2nd claw 16 are equipped. A 1st spring 9 energizing the 1st claw 15 in the direction engaging with the tooth 18 of the driving ring 8 and a 2nd spring 10 energizing the 2nd claw 16 in the direction engaged with the tooth 19 of the main body case 1 are provided. A changeover shaft 11 operated with its rotation with the above 1st claw 15 and 2nd claw 16 being incorporated almost coaxially to the output shaft 12 is equipped.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a ratchet wrench that primarily uses electric power to tighten or loosen bolts, nuts, screws, etc., and more specifically, the present invention relates to a ratchet wrench that primarily uses electric power to tighten or loosen bolts, nuts, screws, etc. This relates to technology that aims to achieve low output.

0002

2. Description of the Related Art Conventionally, an electric or pneumatically driven ratchet wrench, for example an electric ratchet wrench, is equipped with a one-way clutch mechanism that allows one-way feed operation in one of the reciprocating movements, as shown in the Japanese Patent Application Publication No. Showa 59-3
In the No. 0674 publication, the drive ring 8 is reciprocated by rotation of the eccentric shaft 7, and a ratchet pawl 15a is arranged so as to rotate integrally with the output shaft 12 on which a box-like actuator is attached. A ratchet movement is performed to drive and rotate the output shaft 12 only in a certain direction by meshing with the teeth 18 formed on the inner circumference of the drive ring 8 and by the floating spring W that holds the output shaft 12 against the main body case 1 with a predetermined force. It is configured as follows. More specifically, the engagement of the ratchet pawl 15a disposed on the output shaft 12 with the drive ring 8 is switched by a forward/reverse switching shaft 11 coaxially with the output shaft 12 and rotatable within a predetermined range. In the state shown in FIG. 14, the drive ring 8
The teeth 18 of the ratchet pawl 15a engage with each other, and the floating spring W
When the output shaft 12 rotates in the A direction by overcoming the force pressing the output shaft 12 against the main body case 1 and the drive ring 8 rotates in the B direction, the center of swing of the drive ring 8 is aligned with the ratchet pawl 1.
5a and the ratchet pawl 15a.
The spring force of the ratchet spring 9a that presses the output shaft 12 against the drive ring 8 is weaker than the spring force of the floating spring W that presses and holds the output shaft 12 against the main body case 1. The mesh is disengaged and the output shaft 12
maintains its position without rotating. As mentioned above, motor 4
The reciprocating movement of the drive ring 8 in the directions A and B is repeated by the eccentric shaft 7 driven by the eccentric shaft 7, thereby performing the tightening work of bolts, nuts, etc. On the other hand, for loosening work, the direction in which the ratchet pawls 15a engage can be set as shown in FIG. 15 using the forward/reverse switching shaft 11.

0003

However, in such a structure, the spring force of the floating spring W is always applied to the output shaft 12, and this acts as a driving load and outputs the reciprocating motion of the drive ring 8. When converting to rotation of axis 12,
The spring force becomes a mechanical load, reducing the rotation speed and torque. In particular, rechargeable ratchet wrenches have the problem of reducing the number of screws to be tightened and loosened.

The present invention was made in view of these problems, and its purpose is to avoid the use of floating springs, eliminate the mechanical load, and, as a result, reduce the output required for driving. We are trying to provide a ratchet wrench that can.

[0005]

[Means for Solving the Problems] The ratchet wrench of the present invention includes an output shaft 12, an annular drive ring 8 surrounding the outer periphery of the output shaft 12, and a drive ring 8 that is pivotally supported on the output shaft 12.
A first pawl 15 that can freely engage and disengage with teeth 18 formed on the inner periphery of the main body case 1, a second pawl 16 that can engage and disengage freely with teeth 19 formed on the inner periphery of the main body case 1, and a first pawl a first spring 9 that biases the first spring 9 in the direction of meshing the first spring 15 with the teeth 18 of the drive ring 8;
The second spring 10 biases the second pawl 16 in the direction of meshing with the teeth 19 of the main body case 1, and the first pawl 15 and the second pawl 16 are built in and rotate approximately concentrically with respect to the output shaft 12. It is characterized by comprising a switching shaft 11 that is operated, an eccentric shaft 7 that reciprocates the drive ring 8 in the circumferential direction of the output shaft 12, and a motor 4 that rotationally drives the eccentric shaft 7.

[0006]

[Function] As described above, the first pawl 15, which is pivotally supported on the output shaft 12 and can freely engage and disengage with the teeth 18 formed on the inner circumference of the drive ring 8, is used as a ratchet pawl to connect the drive ring 8 to the eccentric shaft 7. By reciprocating with the drive of Teeth 19 formed in
By meshing the second pawl 16 with the second pawl 16, the output shaft 12 is
A second pawl 16 is provided which is integrated with the main body case 1 via the main body case 1 to prevent the return rotation of the output shaft 12, and which can engage and disengage from the teeth 19 formed on the inner peripheral part of the main body case 1 in this manner. In this way, the provision of a conventional floating spring is avoided, the mechanical load caused by the floating spring is avoided, and the output is made small.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below with reference to the drawings. A rechargeable battery pack 3, a motor 4 and a speed reducer 5 are disposed approximately concentrically with each other on a gripping portion 2 of a main body case 1, and a switch 21 is provided between the charging base pack 3 and the motor 4. An eccentric shaft 7 and a drive ring 8 formed at the tip of the drive shaft 6 of the speed reducer 5 constitute a reciprocating mechanism, and a first spring 9 and a second spring
The reciprocating mechanism section together with an output shaft 11 having a switching shaft 11 having a built-in spring 10 rotatably provided therein is rotatably incorporated into the main body case 1 by means of a lid 13 and a retaining ring 14.

Further, a first pawl 15 and a second pawl 16 are pivotally supported on the output shaft 11 by a pawl shaft 17, and the first pawl 15 has teeth 18 formed on the inner circumference of the drive ring 8, The two claws 16 can engage and disengage from teeth 19 formed on the inner periphery of the main body case 1. Here, the first claw 15 and the second claw 16 are provided with teeth 18 and 16, respectively, by a first spring 9 and a second spring 10 covered with a spring cover 20 built into the switching shaft 11.
It is biased in the direction of engagement with 19.

Next, the operation will be explained. When the motor 4 is rotated when the switching shaft 11 is in the forward rotation position as shown in FIG. is converted into a reciprocating motion of the drive ring 8. Here, the drive ring 8
When the is driven and rotated in the direction A in Fig. 3, the first
The pawl 15 meshes with the teeth 18 of the drive ring 8, and the output shaft 12
rotates in the A direction together with the drive ring 8. At this time, the second
As shown in FIG. 4, the pawl 16 is detached from the teeth 19 of the main body case 1 and flipped up, so that the rotation of the output shaft 12 is not hindered. Then, when the drive ring 8 rotates in the direction B,
As shown in FIG.
Fixed. At this time, the first pawl 15 is flipped up in the b direction as shown in FIG. 6, and the drive ring 8 rotates idly to perform a return process of the ratchet operation. The above movements are repeated to tighten bolts, etc.

When the main body case 1 is rotated in the A direction around the output shaft 12 in order to perform manual tightening with the motor 4 stopped, the first pawl is rotated as shown in FIGS. 15, the second claws 16 each have teeth 1 of the drive ring 8
8. The output shaft 12 meshes with the teeth 19 of the main body case 1, and the output shaft 12 rotates in the A direction together with the drive ring 8, that is, the main body case 1. Then, if the main body case 1 is rotated in direction B,
The first claw 15 and the second claw 16 are flipped up, and the main case 1 is rotated idly. By repeating the above operations, it becomes possible to manually tighten bolts and the like.

When the switching shaft 11 is in the reverse position as shown in FIG. Rotate in direction B. At this time, the second pawl 16 is flipped up in the direction a, and does not interfere with the rotation of the output shaft 12 (see FIG. 9). When the drive ring 8 rotates in the direction A, the second pawl 16 moves toward the main body case 1 in the direction b.
The output shaft 12 is fixed to the main body case 1. At this time, the first claw 15 is flipped up in the direction a,
The drive ring 8 becomes idle. By repeating the above movements, bolts etc. are loosened.

When the main body case 1 is rotated in direction B around the output shaft 12 in order to perform manual loosening with the motor 4 stopped, the first pawl 15 and the second pawl 1
6 are teeth 18 of the drive ring 8 and teeth 19 of the main body case 1, respectively.
, and the output shaft 12 rotates in the direction B along with the main body case 1. When the main body case 1 is rotated in the direction A, the first pawl 15 and the second pawl 16 are flipped up and idle. By repeating the above operations, it becomes possible to loosen bolts, etc.

Next, the switching operation between forward and reverse rotation will be explained. As shown in FIG. 10, perpendicular to the axial direction of the switching shaft 11,
A first claw 15 and a second claw 1 are biased by a first spring 9 and a second spring 10 built into the switching shaft 11 via a spring cover 20.
6 is pivotally supported on the output shaft 12, and this first pawl 1
5 has a recess 23 that engages with the spring cover 20 at the center of the surface on the switching shaft 11 side. Here, the first pawl 15 and the second pawl 16 that rotate the switching shaft 11 in the B direction move in the directions shown in FIGS. 3 and 5, and become in a state of screw tightening, that is, a forward rotating body. When the switching shaft 11 is rotated in the A direction, the first pawl 15,
The second pawl 16 moves in the directions shown in FIGS. 8 and 9 and enters a screw tightening state, that is, a reverse rotation state. Further, as shown in FIG. 10, when the spring cover 20 and the recess 23 of the first pawl 15 engage with each other during switching between forward and reverse directions, the first pawl 1
5. The second pawl 16 maintains a neutral state and does not mesh with the teeth 18 of the drive ring 8 or the teeth 19 of the main body case 1.

[0014]

Effects of the Invention As described above, the present invention includes an output shaft, an annular drive ring surrounding the outer periphery of the output shaft, and teeth that are pivotally supported by the output shaft and are engaged with teeth formed on the inner circumference of the drive ring. a first pawl that is removable; a second pawl that can be engaged with and disengaged from teeth formed on the inner circumference of the main body case; and a first spring that biases the first pawl in a direction to engage the teeth of the drive ring. , a second spring biasing the second pawl in the direction of meshing with the teeth of the main body case, and a switching shaft that is rotatably operated and includes the first pawl and the second pawl substantially concentrically with respect to the output shaft. , consists of an eccentric shaft that reciprocates the drive ring in the circumferential direction of the output shaft, and a motor that rotationally drives the eccentric shaft. By using the first pawl that can engage and disengage freely as a ratchet pawl, the drive ring is reciprocated by the drive of the eccentric shaft, and the output shaft is rotated in one direction by driving the drive ring to one side while performing a ratchet movement. During the return movement of the ratchet movement, the teeth formed on the inner circumference of the main body case mesh with the second pawl, thereby integrating the output shaft with the main body case via the second pawl, thereby preventing the return rotation of the output shaft. By providing a second pawl that can freely engage and disengage with the teeth formed on the inner circumference of the main body case, the provision of a conventional floating spring is avoided, and the mechanical load caused by the floating spring is avoided. There is an advantage that the output can be made small.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention.

FIG. 2 is a partially cutaway plan view of the same as the above.

FIG. 3 is an explanatory diagram showing the engagement between the first pawl and the drive ring when the switching shaft is in the normal rotation state.

FIG. 4 is an explanatory diagram showing the engagement between the second claw and the main body case.

FIG. 5 is an explanatory diagram showing the engagement between the second claw and the main body case.

FIG. 6 is an explanatory diagram showing the engagement between the first pawl and the drive ring.

FIG. 7 is an explanatory diagram showing the engagement between the second claw and the main body case.

FIG. 8 is an explanatory diagram showing the engagement between the first pawl and the drive ring when the switching shaft is in a reversed state.

FIG. 9 is an explanatory diagram showing the engagement between the second claw and the main body case.

FIG. 10 is an explanatory diagram showing the first claw and the second claw of the same as above in a neutral state.

FIG. 11 is an overall side sectional view of a conventional example.

FIG. 12 is a side view of the same as above.

FIG. 13 is a partial sectional view of the same as above.

FIG. 14 is an explanatory diagram showing the engagement between the ratchet pawl and the drive ring.

FIG. 15 is an explanatory diagram showing the engagement between the ratchet pawl and the drive ring.

[Explanation of symbols]

1 Main body case 4 Motor 7 Eccentric shaft 8 Drive ring 9 First spring 10 Second spring 11 Switching axis 12 Output shaft 15 First claw 16 Second claw 18 Teeth 19 Teeth

Claims (1)

[Claims] 1. An output shaft, an annular drive ring surrounding the outer periphery of the output shaft, a first pawl that is pivotally supported on the output shaft and that can freely engage and disengage with teeth formed on the inner circumference of the drive ring; A second pawl that can engage and disengage freely with the teeth formed on the inner circumference of the main body case, a first spring that biases the first pawl in a direction to engage with the teeth of the drive ring, and a second pawl that is attached to the main body case. a second spring that biases in the direction of meshing with the teeth; and a second spring that is substantially concentric with the output shaft.
A ratchet wrench consisting of a switching shaft that includes a pawl and a second pawl and is rotatably operated, an eccentric shaft that reciprocates a drive ring in the circumferential direction of an output shaft, and a motor that rotationally drives the eccentric shaft.