Clutch mechanism and power tool
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- NITTO KOHKI CO LTD
- Filing Date
- 2020-09-11
- Publication Date
- 2026-07-02
AI Technical Summary
Existing clutch mechanisms in power tools are limited by the need for multiple types of components with different sizes and locations to adjust maximum torque, leading to increased costs and complexity in changing torque settings.
A clutch mechanism with adjustable torque settings using first and second clutch plates and engaging members that can be selectively positioned in inner or outer holding holes, allowing for changing maximum torque without replacing components, and a power tool incorporating this mechanism.
Enables adjustable torque settings through simple assembly choices, reducing component variety and complexity, and provides efficient torque control with wear detection and adjustment.
Abstract
Description
Technical area:
[0001] The present invention concerns a clutch mechanism to limit the torque transferred from an input shaft to an output shaft as well as a power -driven tool or an electric tool with a clutch mechanism. Background of the invention:
[0002] For electric tools, such as an electric motor driven screwdriver with an electric motor as a drive unit and a compressed air drill with a compressed air engine as a drive unit, there is an electric tool with a clutch mechanism that is between a rotating or rotating drive shaft of a drive unit and one with a machining tool, such as a screwdriver use or -Bit or a drilling insert or bit, stocked output shaft is intended to limit the maximum torque applied by the drive unit to the output shaft (patent literature 1 and 2). If, for example, an electromotically driven screwdriver is provided with a clutch mechanism to limit the torque attached to a screw using a screwdriver insert, damage to the screw can be prevented. It is also possible to stop the drive of an engine or to count the number of screws attracted by assessing the completion of a screw -up process if the clutch mechanism solves the drive connection in response to a quick increase in the torque, which results from the insertion of the screw.
[0003] The clutch mechanism of the electromotor -driven screwdriver described above, for example, has a clutch ball that is arranged on the side of the output shaft, so that the clutch ball can be inserted into the direction of the drive with a lead of a rotating or rotating clutch element on the side of the drive shaft. The clutch ball is pressed or prayed in the direction of the coupling element by means of a spring in order to maintain a state in which the clutch ball with the lead is inserted. While the clutch ball is interfered with the lead in the direction of rotation, a torque is transferred from the rotating drive shaft to the output shaft. If or as soon as an excessive torque occurs, the clutch ball is moved in the direction of the axis of rotation against the pressure or preloading force of the spring in order to cancel the intervention between the clutch ball and the lead in the direction of rotation, which means that the transmission of the torque is lifted. Quoter list: patent literature: Patent literature 1: WO2017 / 038846 Patent literature 2: Japanese patent application with publication no. 2017-42878 Summary of the invention: Technical problem:
[0004] The maximum torque that the clutch mechanism can transmit depends, for example, on the preload of the spring, the shift or excavation amount of the clutch ball when the clutch mechanism and the position in the radial direction depend on the clutch ball into the lead of the coupling element. Therefore, the maximum torque that the clutch mechanism can transmit can be changed, for example by changing the size or arrangement of the clutch ball. However, it is not possible to replace the clutch ball with a different ball with a different size, since the size of a stop hole for the intake of the clutch ball is usually tailored to the size of the clutch ball or is therefore compliant. Since the position of the clutch ball is also determined by the position of the stop hole, the position of the clutch ball cannot be moved. Accordingly, it is necessary to construct clutch mechanisms with different maximum torque, prepare a variety of different types of elements, have the clutch ball holes with different sizes and / or at different positions, and selectively use the prepared elements in accordance with the necessary maximum torque. As a result, the number of different types of components increases that must be prepared, which leads to an increase in costs. In addition, in the event of a later or subsequent change in the maximum torque, not only the clutch ball, but also an element to hold or withdraw the clutch ball, leads to a complicated process.
[0005] Under these circumstances, it is a goal of the present invention to provide a clutch mechanism that enables the maximum transferable torque to be changed without changing a component that holds or holds back an intervention element (clutch ball) and also provides an electric tool that has such a coupling mechanism. Solution of the problem:
[0006] This means that the present invention provides a clutch mechanism that is set up that it is arranged between an input shaft and an output shaft in order to limit a torque transferred from the input shaft to the output shaft, whereby the clutch mechanism has the following: a first clutch plate that is set up with the input wave or drive -to -drive to be or become, the first clutch plate is arranged in such a way that it can be rotated by a axis of rotation and has a leading advantage that heads towards the axis of rotation; A second coupling plate, which is set up, with which others from the entrance shaft and the output shaft can be connected or to be connected to each other, whereby the second clutch plate is arranged in such a way that it is opposite the first clutch plate in the direction of the axis of rotation and is rotatable around the axis of rotation, whereby the second coupling plate is an inner stop hole, which extends through it in the direction of the loft, and has an outer stop hole that stretches through it in the direction of the axis of rotation, the outer stop hole further radially positioned as the inner stop hole is positioned; an intervention element that is selectively arranged in a stop hole, in the inner stop hole or in the outer stop hole, whereby the intervention element in one stop hole is kept so that it can be moved in the direction of the axis of rotation; And a sliding element that lies against the intervention element in the direction of the axis of rotation to push the intervention element of the first coupling plate. The coupling mechanism is set up to transfer a torque between the first clutch plate and the second clutch plate by intervening the intervention element with the intervention advantage into a direction of rotation. If a load is that is the same or greater than a pre -determined maximum torque, the intervention advantage causes the intervention element together with the sliding element in the direction of the axis of rotation in order to lift the intervention between the procedure and the intervention element in the direction of rotation, which means that the transmission of the torque is canceled. The maximum rotary torque is greater if the intervention element is selectively arranged in the outer stop hole than if the intervention element is selectively arranged inside.
[0007] In the coupling mechanism, an inner stop hole and an outer stop hole are trained in the second coupling plate, which is further externally positioned as the inner hold hole, and an intervention element is selectively arranged in a stop hole, namely the inner stop hole or the outer stop. Simply selecting whether the intervention element should be arranged in the interior of the inner stop or in the outer stop hole, it is possible to change the maximum torque that the clutch mechanism can transmit without replacing the second coupling plate.
[0008] Furthermore, the arrangement can look as follows. The outer stop hole has a larger diameter than the inner stop hole, and the intervention element is a spherical intervention element, selected from a spherical intervention element with a small diameter that corresponds to the inner stop hole, and a spherical intervention element with a large diameter that has a larger diameter than the insert element with a small diameter and that corresponds to the outer stone hole, so that the selected spherical intervention element corresponds to the one stop hole.
[0009] With the arrangement described above, the difference between the adjustable maximum torque can be further enlarged, although it is necessary to prepare spherical intervention elements with different sizes.
[0010] Furthermore, the arrangement can be as follows. The first coupling plate has an inner intervention area that is set up, that it comes into intervention with the spherical intervention element with a small diameter when the spherical interference element is arranged with a small diameter in the inner hold hole, and an outer intervention area that is set up with the spherical intervention element with a large diameter when the spherical The intervention element with a large diameter is arranged in the outer stop hole, whereby the inner intervention area in the direction of the second coupling plate continues by an amount than the outer intervention area, which corresponds to a diameter difference between the spherical interference element with a small diameter and the spherical intervention element with a large diameter.
[0011] In addition, the present invention provides a clutch mechanism that is set up to be arranged between an input shaft and an output shaft in order to limit a torque transmitted from the entrance shaft to the output shaft, whereby the clutch mechanism has the following: A first coupling plate that is set up with the input shaft or the output shaft to be or to be connected or drive -to -drive, whereby the first coupling plate is arranged in such a way that it can be rotated by a axis of rotation and has a leading advantage that presents in the direction of the axis of rotation; A second coupling plate, which is set up, to be or to be connected to each other by the entrance shaft and the output shaft, whereby the second coupling plate is arranged in such a way that it is opposite the first coupling plate in the direction of the axis of rotation and is rotatable around the axis of rotation, whereby the second coupling plate with a small diameter, which is through it in the direction of the wreath stretches, and has a hold hole with a large diameter that stretches through it through it in the direction of the axis of rotation, whereby the stop hole with a large diameter has a larger diameter than the stop hole with a small diameter; An intervention element, which corresponds to the stop hole with a small diameter, and an intervention element with a large diameter, which corresponds to the stop hole with a large diameter, the intervention element with a large diameter has a larger diameter than the intervention element with a small diameter, whereby the intervention element in a corresponding stone hole or with a small diameter or with small diameter the stop hole with a large diameter, is arranged and is kept in the corresponding stop hole in such a way that it can be moved in the direction of the axis of rotation; And a sliding element that lies against the intervention element in the direction of the axis of rotation to press the intervention element in the direction of the first coupling plate. The clutch mechanism is set up to transmit a torque between the first clutch plate and the second clutch plate by intervening the intervention element with the intervention advantage in a direction of rotation. When a load is available that is larger or the same as a predetermined maximum torque, the procedure leads that the intervention element is moved together with the sliding element in the direction of the axis of rotation in order to lift the intervention between the intervention advantage and the intervention element in the direction of rotation, which means that the transmission of the torque is lifted. The maximum rotary torque is larger if the intervention element with a large diameter is selectively arranged in the stop hole with a large diameter, as if the intervention element is selectively arranged in the stop hole with a small diameter.
[0012] In the clutch mechanism, a stop hole with a small diameter and a stop hole with a large diameter, the diameter of which is larger than that of the stop hole with a small diameter, is formed in the second coupling plate, and one of a small diameter and an intervention element with a large diameter is selectively arranged in the corresponding stop hole. Simply selecting whether the intervention element with a small diameter in the stop hole with a small diameter or whether the intervention element with a large diameter in the stop hole with a large diameter when assembled or assembly is to be arranged, it is possible to change the maximum torque that can transmit the coupling mechanism without replacing the second coupling plate.
[0013] In addition, the present invention provides a power-driven or electric tool that has the following: a drive unit with an input shaft; an output shaft with a tool attachment part to be attached to which a machining tool must be attached; and the clutch mechanism described above, which is arranged between the entrance shaft and the output shaft.
[0014] Implactions of an electric tool according to the present invention are explained below based on the attached drawings. Figure list Fig. 1 is a cut view of an electromotor -driven screwdriver according to an embodiment of the present invention. Fig. 2 is a functional block diagram of the in Fig. 1 shown electromotor -driven screwdriver. Fig. 3 is an enlarged view that a clutch mechanism of the electromotor -driven screwdriver in Fig. 1 and the surroundings of the clutch mechanism shows. Fig. 4 is an enlarged view of the clutch mechanism and its surroundings, which shows a state in which a cylindrical wave section of a output shaft was inserted. Fig. 5 is a perspective explosion of components that make up the clutch mechanism in a top view. Fig. 6 is a perspective explosion of components that make up the clutch mechanism in a view from below. Fig. 7 is an enlarged view of the clutch mechanism and its surroundings, which shows a state in which the clutch mechanism has been solved or unlocked to remove the transmission of a torque. Fig. 8 is a flow diagram that shows a process to determine a state of wear. Fig. 9 is an enlarged view that shows the clutch mechanism and its surroundings when spherical intervention elements with a small diameter are arranged in inner holding elder. Fig. 10 is an enlarged view of the clutch mechanism and its surroundings in Fig. 9 that shows a state in which the coupling of the coupling mechanism was solved to abolish the transmission of a torque. Description of the embodiment:
[0015] Like in Fig.1 is shown that an electromotically driven screwdriver (electrical tool) 1 according to an embodiment of the present invention is the following: a tool housing 10, an electric motor (drive unit) 12, which is arranged in the tool housing 10, a output or output shaft 16 with a tool mounting part, on which a screw-on or-bit use or bit (Processing tool) It is removable to transfer a planetary gear mechanism 20 that is set up to transmit the rotation of a rotating or rotating drive shaft (input shaft) 18 of the electric motor 12, while reducing its speed, and a clutch mechanism 22, which is arranged between the planetary gear mechanism 20 and the output shaft 16. The torque of the electric motor 12 is transferred to the output shaft 16 via the planetary gear mechanism 20 and the clutch mechanism 22. The tool housing 10 is also provided with a photo -electrical start sensor 24 to start the drive of the electric motor 12 and a photo -electric brake sensor 26 to stop the drive of the electric motor 12. The drive and stopping of the electric motor 12 are controlled on the basis of the output values of the photoelectric sensors 24 and 26, as explained below.
[0016] A tax circuit 28 arranged in the tool housing is 28, as in Fig. 2 shown, equipped with a computing unit 30, an engine control unit 32 for drive control of the electric motor 12 and a memory 34 for saving a control program, tax parameters, etc. The photo -electrical start sensor 24 and the photo -electrical brake sensor 26 are connected to the computing unit 30, and the computing unit 30 controls the start and stop of the drive of the electric motor 12 based on the output values of the photoelectric start sensor 24 and the photo -electrical brake sensor 26. is arranged for the worker clearly visible. The error display 36 has an LED, and if some errors occur, the error display 36 shows the worker the fault states through LED light radiation. It should be noted that the photo -electrical start sensor 24 has a light -emitting part (not shown) and a light receiving part 24a, which are opposite each other, and that the light receiving part 24a receives light, which is emitted by the light emitting part and issues an output value that corresponds to the amount of light received. Similarly, the photo -electrical brake sensor 26 has a light -emitting part (not shown) and a light receiving part 26a, which are opposite each other, and the light receiving part 26a receives the light emitted by the light -emitting part and issues an output value that corresponds to the amount of light received. In this embodiment, the photo -electrical start sensor 24 and the photo -electrical brake sensor 26 are set up in such a way that the output value increases accordingly if the amount of light, which is received by the light receiving part 24a, 26a, decreases, whereby the output value increases accordingly.
[0017] Like in Fig.3 shown, the output shaft 16 shows a full wave section 38, which is connected to the clutch mechanism 22, and a cylindrical wave section 40 that is arranged in such a way that it glides on an outer extent area 38a of the full wave section. The full wave section 38 and the cylindrical wave section 40 are fixed in the direction of rotation. Bug-shaped locking elements 44 are arranged in locking element element stops or backlocks 42, which are formed in the cylindrical wave section 40, and a sleeve 46 is arranged on an external circumference 40a of the cylindrical wave section 40. If the sleeve 46 is moved from the position shown in the direction of the distal end side (in the figure the lower side), the locking elements 44 can be moved radially outwards. If a screwdriver insert or bit is inserted into an operational or introductory hole 48 of the cylindrical wave section 40 and the sleeve 46 is brought back to the original position, the screwdriver insert is attached to the output shaft 16. The tool attachment part 14 of the output shaft 16 thus has the cylindrical wave section 40, the locking elements 44 and the sleeve 46. If the tool housing 10 is used in a state in which the screwdriver insert is attached to the tool attachment part 14 and is operated in such a way that the screw connection is pressed against a screw, the cylindrical wave section 40 of the output shaft 16 is pushed into the tool housing, as in Fig. 4 is shown. If or as soon as the cylindrical wave section 40 is pushed into, a circuit diagram 52, which is arranged on a rear section 50 of the cylindrical wave section 40, is also moved together with the cylindrical wave section 40. As a result, circuit diagram 52 occurs between the light -emitting part and the light receiving part 24a of the photoelectric starting sensor 24 in order to partly block the light emitted by the light -emitting part in the direction of the light receiving part 24a. With increasing penetration of the circuit diagram 52, the amount of light received from the light receiving part 24a decreases, and the output value of the photo electrical start sensor increases. The computing unit 30 starts the drive of the electric motor 12 if or as soon as it receives an output value from the photoelectric start sensor 24, which is greater than a predetermined starting threshold value (a signal that indicates the drive start).
[0018] The coupling mechanism 22 has a first coupling plate 54, which is connected to the rotating drive shaft 18 of the electric motor 12 via the planetary gear mechanism 20, and a second coupling plate 56, which is connected to the full wave section 38 of the output shaft 16. The first coupling plate 54 and the second coupling plate 56 are arranged in such a way that they can be rotated around a axis of rotation. The second coupling plate 56 is arranged so that it is opposite the first clutch plate 54. Like in the Fig. 5 and Fig.6 Displayed, the first clutch plate 54 radially running and retention guards 58, which are formed in one of the second clutch plate 56 facing face 55. The keepers 58 have been set up that they hold ring -shaped column -shaped intervention elements (procedures) 60, which stretch in the radial direction to the axis of rotation R, keep or hold back in them. In the second coupling plate 56, there are two inner holding holes (holding holes with a small diameter) 62, which extend through them in the direction of the axis of rotation, and two outer stop holes (holding holes with a large diameter) 64, which extend in the direction of the axis of the rotation through them. The outer holding holes 64 are located radially further outside than the inner holding holes 62. The outer holding holes 64 show a larger diameter than the inner stop holes 62. The inner holding holes 62 are set up, each spherical interfering elements with a small diameter (intervention elements) 66, and the outer holding holes 64 are set up, each spherical intervention elements with a large diameter (interference elements) 68, which have a larger diameter than the spherical interfering -shaped 66 with a small diameter. However, it should be noted that only one of the two types of intervention elements is used. Accordingly, one of the two types of intervention elements is selected when the electromotically driven screwdriver 1 is assembled, i.e. the spherical interference elements 66 with a small diameter that correspond to the inner holding anche 62, and the spherical intervention elements 68 with a large diameter that corresponds to the outer holding holes 64, and only the selected intervention is each arranged in the corresponding stop. In the Fig. 1 and Fig. 3 The spherical intervention elements 68 with a large diameter of each selectively arranged in the outer stops 64. Like in Fig. 6 shown on the front surface 55 of the first coupling plate 54 An inner intervention area 55a, which is set up, are to be reached with the spherical intervention elements 66 with a small diameter if these are arranged in the inner holding anches 62, and an external intervention area 55B, which is formed, with the spherical intervention elements 68 with large diameter in Interference to come when they are arranged in the outer stops 64. The inner intervention area 55a protrudes in the direction of the second coupling plate 56 by an amount than the outer intervention area 55b, which corresponds to the diameter difference between the spherical intervention elements 66 with a small diameter and the spherical intervention elements 68 with a large diameter. The above heights of the spherical intervention elements 66 with a small diameter and the spherical intervention elements 68 with a large diameter of the second coupling plate 56 are equally, if the spherical intervention elements 66 with a small diameter and the spherical intervention elements 68 with a large diameter 62 or in the outer stance os 64 are.
[0019] Like in Fig.3 shown, the clutch mechanism 22 also has a shift element 70 that is arranged in such a way that it can be moved towards the second clutch plate 56 and the full wave section 38 of the output shaft 16 in the direction of the axis of rotation. The shift element 70 has a sliding element 72 that is set up to slide on the outer extent area 38a of the full wave section 38 in the direction of the axis of rotation R, a pressure recording element 76, which can be rotated by a warehouse 74 relative to the glide element 72, and a sensor pen 80, which is pressed against the pressure recording element 76, so that it is connected with the gliding element 72 and the pressure recording element 76 is moved towards the axis of rotation R. The pressure recording element 76 of the shift element 70 is pressed by a clutch spring 82 against the second coupling plate 56 by means of a transmission pen 84. The spherical intervention elements 68 with a large diameter are on an intervention area 72a of the sliding element 72 and are therefore pressed by the pressure recording element 76 and the sliding element 72 in the direction of the first coupling plate 54 and the ring -shaped column -shaped intervention elements 60.
[0020] If the cylindrical wave section 40 of the output shaft 16 as in Fig. 4 Showed and the drive of the electric motor 12 is launched, the first coupling plate 54, which is connected to the rotating drive shaft 18 of the electric motor 12 via the planetary gear mechanism 20, and the ring -shaped column -shaped intervention elements 60 around the axis of rotation R. As a result, the ring -shaped column -shaped intervention elements 60 in the rotary seal intervenes into the spherical intervention elements 68, and a torque is transferred to the second coupling plate 56 via the spherical intervention elements 68. Since the second coupling plate 56 is attached to full wave section 38 of the output shaft 16, the torque is transferred to the output shaft 16. The ring -shaped column -shaped intervention elements 60 and the spherical intervention elements 68 are in intervention by curved surfaces, and when the torque is transmitted, the spherical intervention elements 68 get a force from the ring -shaped column -shaped intervention elements 60, in the direction of the rotary poll -shaped interference. the spherical intervention elements 68 are pressed by the clutch spring 82 towards the first coupling plate 54. Therefore, while the power, the spherical intervention elements 68 from the ring -shaped column -shaped intervention elements 60 in the direction of the rotary axis R, lies within the area of the pressure force of the coupling spring 82, the spherical intervention elements 68 are not shifted in the direction of the rotary axis R, and the condition is retained in which the ring -shaped column -shaped Interfering elements 60 and the spherical intervention elements 68 in the direction of rotation are interfered with and in which the rotary torque is thus transmitted.
[0021] If the clutch mechanism 22 is placed with a load that is the same or larger than a pre -determined maximum torque, the spherical intervention elements 68 are pressed in the direction of the axis of rotation by the ring -shaped column -shaped interference elements and thus moved in one direction (as can be seen in the figure) from the first coupling plate 54 Shifting element 70, while the clutch spring 82 is pressed together. When the spherical intervention elements 68 are moved so that they run entirely on the ring -shaped column -shaped intervention elements 60, as in Fig.7 shown, then the intervention between the ring -shaped column -shaped intervention elements 60 and the spherical intervention elements 68 in the direction of rotation is canceled, and the transmission of the torque from the first coupling plate 54 to the second coupling plate 56 is also temporarily canceled. At this point, the sensor pen 80 of the shift element 70 occurs between the light -emitting part and the light receiving part 26a of the photo -electrical brake sensor 26. Consequently, the sensor pin 80 blocks partly from the light -emitting part 26a emitted light. In this embodiment, the output value of the photoelectric brake sensor 26 increases according to the decrease in the received amount of light if or as soon as the amount of light received by the light receipt decreases. Therefore, the computing unit 30 can determine the position of the sensor monastery 80 between the light -emitting part and the light receiving part 26a based on the output value of the photo -electric brake sensor 26. If the output value of the photo -electrical brake sensor 26 exceeds a predetermined reference value for the release specification, the computing unit 30 determines that the clutch mechanism was released 22 to remove the transmission of the torque and stops the drive of the electric motor 12.
[0022] In the clutch mechanism 22, the ring -shaped column -shaped intervention elements 60 and the spherical intervention elements 68 rub against each other, while they are pressed together by a relatively large force. Therefore, the ring -shaped column -shaped intervention elements 60 and the spherical intervention elements 68 will gradually be worn out if the electromotically driven screwdriver 1 is used repeatedly. Mutual rubbing also occurs between the spherical intervention elements 68 and the sliding element 72 as well as between the sliding element 72 and the pressure recording element 76; Therefore, these elements will probably also be worn out. If or if the components of the coupling mechanism 22 have been worn out in this way, there is a reduction in the entry quantity of the sensor pen 80 between the light -emitting part and the light receiving part 26a of the photoelectric brake sensor 26, if the transmission of the torque by the clutch mechanism 22 As a result of the emergence of the spherical interference elements 68 to the ring -shaped Column -shaped intervention elements 60 is canceled. In the electromotor -driven screwdriver 1, the computing unit 30 monitors the output value of the photoelectric brake sensor 26 and captures the position of the sensor pen 80 between the light emitting part and the light receiving part 26a on the basis of the output value of the photo -electrical brake sensor 26, which determines the wear and conditions of the coupling mechanism 22.
[0023] Determination of the wear state of the electromotor -driven screwdriver 1 takes place in particular by a process, which in the flow diagram of Fig.8 is shown. If the electromotically driven screwdriver 1 is connected to a power supply, the computing unit 30 is activated (S10). The computing unit 30 monitors the output value of the photo electrical starting sensor 24, and if the output value of the photoelectric start sensor is greater than a predetermined start -up wave value (S12), the computing unit is determined that the screw -mounted application attached to the tool attachment part was pushed or pushed into it, and starts the rotating drive of the electric motor 12 (S14). Next, the computing unit 30 monitors the output value of the photo -electrical brake sensor 26, and if the output value of the photoelectric brake sensor 26 is greater than a predetermined reference value for the release determination (S16) and then returns to a value that is no greater than the reference value for the release determination (S17), the computer unit saves in the memory 34 (S18) A maximum output value with the largest difference to the reference value for the release determination under the output values that were obtained during the period and stops the drive of the electric motor 12 (S20). The computing unit 30 monitors the output value of the photo -electrical start sensor 24 again, and if the output value of the photo electrical start sensor 24 changes to a value that is larger than the photo -electrical start sensor (S22), the computing unit 30 compares the maximum output value of the photo -electrical brake sensor 26, which was saved in storage 3 with a predetermined reference value Determination of wear (S24). If the maximum output value has increased to the same or greater than the reference value to wear determination, the computing unit 30 determines that the sensor pen 80 has been postponed to a sufficiently large extent and that the clutch mechanism 22 was not very worn out, and resumes the drive of the electric motor 12 (S14). If, on the other hand, the maximum output value has not reached the reference value for the determination of wear and is therefore smaller than the reference value for wear determination, the computing unit 30 notes that the sensor pen 80 has not been sufficiently postponed and the clutch mechanism 22 is thus worn out, and creates an error signal (S26). When the error signal is created, the error display 36 lights up to indicate that the wear of the clutch mechanism 22 has progressed beyond a certain level or level. In this case, the drive of the electric motor 12 is not started. It should be noted that the photo -electrical start sensor 24 and the photo -electrical brake sensor 26 can be set up in such a way that the output value decreases if the amount of light received by the light -recipient part decreases. In this case, the drive of the electric motor 12 is started when the output value of the photoelectric starting sensor 24 changes to a value below the start -up wave value. If the output value of the photo -electric braking sensor 26 also changes to a value that is smaller than the reference value for the triggering determination, and then returns to a value that is the same or greater than the reference value for triggering determination, the computing unit 30 determines that the clutch mechanism has been solved and creates an error signal if a minimal output value with the largest difference to the reference value has been For triggering under the output values that were obtained during the period, it has not reached a value that is not greater than the reference value for wear determination, but is greater than the reference value for wear determination. It should be noted that when assessing the wear state, the progression of the wear in three or more stages or in analoges can be displayed on the basis of the output value of the photoelectric brake sensor 26 instead of only displaying two conditions, i.e. whether the wear has exceeded a fixed amount or not.
[0024] Like in the Fig. 9 and Fig.10 shown, the electromotually driven screwdriver can be assembled by arranging the spherical intervention elements 66 with a small diameter instead of the spherical intervention elements 68 with a large diameter of 62. As explained above, the spherical intervention elements 66 arranged in the inner holding elements 62 with a small diameter of 55a intervene, which is more than the outer intervention area 55b on the forehead surface 55 of the first coupling plate 54. As a result, the shift element 70 of the coupling mechanism 22 in the in Fig. 9 in which the clutch mechanism 22 is not solved, the same position as in Fig. 3 in which the spherical intervention elements 68 are arranged with a large diameter. Accordingly Fig. 3. On the other hand, in the in Fig. 10 state shown in which the clutch mechanism 22 was solved, the amount of the shift in the shift element 70 smaller than in the arrangement of Fig. 7, in which the spherical intervention elements 68 are arranged with a large diameter. Accordingly, the amount of the sensor pen 80 between the light -emitting part and the light receiving part 26a of the photo electrical brake sensor 26 is smaller than in the in Fig. 7 shown. Therefore, if the spherical intervention elements 66 are selectively arranged with a small diameter, the reference value for the release of the release and the reference value for wear determination is set to smaller values than in the case in which the spherical intervention elements 68 are selectively arranged with a large diameter.
[0025] Since the amount of the shift of the shift element is 70 smaller if the clutch mechanism 22 is solved, the clutch mechanism 22 can be solved with a smaller torque. In addition, the coupling mechanism 22 can be solved with a smaller torque, since the position at which each spherical intervention element 66, 68 inserts into the associated ring -shaped column -shaped intervention element 60, relative to the axis of the rotation R further radially. Accordingly, with the electromotically driven screwdriver 1, the coupling mechanism 22 is solved with a smaller torque if the spherical intervention elements 66 with a small diameter is selectively arranged in the inner holding elements 62 than if the spherical intervention elements 68 are selectively arranged in the external stalks 64. In other words, the size of the maximum torque that the coupling mechanism 22 can transmit can be changed using whether the spherical intervention elements 68 with a large diameter in the outer holding elements 64 or the spherical intervention elements 66 with a small diameter in the inner holding element 62. It should be noted that the same intervention elements can be used as an intervention elements that are to be arranged in the inner holding elements, and those that are to be arranged in the outer holding elements by making the inner holding holes and the outer holding holes in the same size. In this case, the radial positions at which the intervention elements intervene in the ring -shaped column -shaped intervention elements 60 differ from one another, the maximum rotary torque can be set to different sizes or sizes. Alternatively, the stops with a small diameter and the holding holes with a large diameter can be trained in the same position in the radial direction. In this case, the arranged intervention elements are different in size, and there is a difference in the size of the displacement of the shift element 70 until the clutch mechanism is released. Therefore, the maximum torque can be set to different sizes or sizes. However, it should be noted that the difference between adjustable maximum torque can be further enlarged by designing the holding holes differently in terms of the radial position and also by designing the intervention elements of different sizes, as in the previous embodiment.
[0026] Although some embodiments of the present invention have been explained above, the present invention is not limited by these embodiment. For example, the ring -shaped column -shaped intervention elements that form the procedure can have a spherical or other shape, for example instead of ring -shaped column -shaped, or they can be formed in a piece with the first coupling plate as sections that protrude from the first coupling plate. The arrangement can also be in such a way that the ring -shaped column -shaped intervention elements are connected to the output shaft side, and the intervention elements are connected to the input wave side, so that if the clutch mechanism is solved, the shift element is moved towards the input wave side. Although the electrical tool is also explained in the above versions as an electromotically driven screwdriver with an electric motor as a drive unit, the present invention can also be used as an example of other electricity tools than the electromotor-powered screwdriver, e.g. B. an electromotor driven drilling machine or an electric motor -driven polishing machine, or other power tools such as a compressed air tool with a compressed air engine as a drive unit. In addition, the clutch mechanism can also be used in other mechanical constructions as electric tools. Reference sign list 1 electromotor-driven screwdriver (electric tool) 10 tool housing 12 electric motor (drive unit) 14 tool attachment part 16 output or output shaft 18 rotating drive shaft (input shaft) 20 planetary gears or planetary gear mechanism 22 coupling mechanism 24 photoelectric start sensor 24a light -recipient part 26 Photo -electrical brake sensor 26a light receiving part 28 Tax circuit 30 computing unit 32 engine control unit 34 memory 36 error display 38 full wave section 38a outer circumference area 40 cylindrical wave section 40A outer circumference area 42 locking element holding or back holders 44 locking elements 46 sleeve 48 operational or introductory hole 50 rear end section 52 circuit board 54 First clutch plate 55 front surface 55a inner intervention area 55b external intervention area 56 second coupling plate 58 holding sites 60 ring -shaped column -shaped intervention elements (intervention advances) 62 inner holding holes (holding holes with a small diameter) 64 outer holding holes (holding holes with a large diameter) 66 spherical intervention elements with a small diameter (intervention elements) 68 spherical intervention elements with a large diameter (intervention elements) 70 shift element 72 sliding element 72a intervention area 74 camp 76 pressure recording element 78 feather 80 sensor pen 82 clutch spring 84 transmission pen R rotary axis Quotes contain in the description
[0000] This list of documents listed by the applicant was automatically created and is only included in the reader's better information. The list is not part of the German patent or utility model registration. The DPMA assumes no liability for any errors or omissions. Cited patent literature
[0000] Where 2017 / 038846
[0003] JP 201742878
[0003]
Claims
[1] A clutch mechanism adapted to be disposed between an input shaft and an output shaft to limit a torque transmitted from the input shaft to the output shaft, the clutch mechanism comprising: a first clutch plate configured to be drivably connected to one of the input shaft and the output shaft, the first clutch plate being arranged to be rotatable about a rotational axis and having an engagement projection projecting toward the rotational axis; a second clutch plate configured to be drivably connected to a respective other one of the input shaft and the output shaft, the second clutch plate being arranged to oppose the first clutch plate in the direction of the rotation axis and to be rotatable about the rotation axis, the second clutch plate having an inner retaining hole extending therethrough in the direction of the rotation axis and an outer retaining hole extending therethrough in the direction of the rotation axis, the outer retaining hole being positioned radially further outward than the inner retaining hole; an engaging member selectively disposed in one of the inner holding hole and the outer holding hole, the engaging member being held in the one holding hole so as to be displaceable in the direction of the rotation axis; and a sliding member abutting against the engaging member in the direction of the rotation axis to urge the engaging member toward the first clutch plate; wherein the clutch mechanism is configured to transmit a torque between the first clutch plate and the second clutch plate by engagement of the engagement element with the engagement projection in a rotational direction, and wherein the engagement projection causes, when a load equal to or greater than a predetermined maximum torque is applied, the engagement element to be displaced together with the sliding element in the direction of the rotational axis to cancel the engagement between the engagement projection and the engagement element in the rotational direction, thereby canceling the transmission of the torque; and wherein the maximum rotational torque is greater when the engagement element is selectively disposed in the outer retaining hole than when the engagement element is selectively disposed in the inner retaining hole. [2] The clutch mechanism according to claim 1, wherein the outer holding hole has a larger diameter than the inner holding hole, and wherein the engaging member is a spherical engaging member selected from a small-diameter spherical engaging member corresponding to the inner holding hole and a large-diameter spherical engaging member having a larger diameter than the small-diameter engaging member and corresponding to the outer holding hole, such that the selected spherical engaging member corresponds to the one holding hole. [3] The clutch mechanism according to claim 2, wherein the first clutch plate has an inner engagement surface configured to engage with the small-diameter spherical engagement element when the small-diameter spherical engagement element is disposed in the inner holding hole, and an outer engagement surface configured to engage with the large-diameter spherical engagement element when the large-diameter spherical engagement element is disposed in the outer holding hole, wherein the inner engagement surface protrudes toward the second clutch plate by an amount further than the outer engagement surface corresponding to a diameter difference between the small-diameter spherical engagement element and the large-diameter spherical engagement element. [4] A clutch mechanism adapted to be disposed between an input shaft and an output shaft to limit a torque transmitted from the input shaft to the output shaft, the clutch mechanism comprising: a first clutch plate configured to be drivably connected to one of the input shaft and the output shaft, the first clutch plate being arranged to be rotatable about a rotational axis and having an engagement projection projecting toward the rotational axis; a second clutch plate configured to be drivably connected to a respective other one of the input shaft and the output shaft, the second clutch plate being arranged to oppose the first clutch plate in the direction of the rotation axis and to be rotatable about the rotation axis, the second clutch plate having a small-diameter holding hole extending therethrough in the direction of the rotation axis and a large-diameter holding hole extending therethrough in the direction of the rotation axis, the large-diameter holding hole having a larger diameter than the small-diameter holding hole; an engagement element selected from a small-diameter engagement element corresponding to the small-diameter holding hole and a large-diameter engagement element corresponding to the large-diameter holding hole, the large-diameter engagement element having a larger diameter than the small-diameter engagement element, the engagement element being arranged in a corresponding holding hole, namely the small-diameter holding hole or the large-diameter holding hole, and held in the corresponding holding hole so as to be slidable in the direction of the rotation axis; and a sliding member abutting against the engaging member in the direction of the rotation axis to urge the engaging member toward the first clutch plate; wherein the clutch mechanism is configured to transmit a torque between the first clutch plate and the second clutch plate by engagement of the engagement element with the engagement projection in a rotational direction, and wherein the engagement projection causes, when a load greater than or equal to a predetermined maximum torque is applied, the engagement element to be displaced together with the sliding element in the direction of the rotational axis to release the engagement between the engagement projection and the engagement element in the rotational direction, thereby releasing the transmission of the torque; and wherein the maximum rotational torque is greater when the large diameter engaging element is selectively disposed in the large diameter retaining hole than when the small diameter engaging element is selectively disposed in the small diameter retaining hole. [5] A power tool or electric tool having: a drive unit with an input shaft; an output shaft with a tool attachment part to which a machining tool is to be attached; and the clutch mechanism according to any one of claims 1 to 4, wherein the clutch mechanism is arranged between the input shaft and the output shaft.