CN113905833A

CN113905833A - Method for cyclically controlling a punch of a punching tool and punching tool

Info

Publication number: CN113905833A
Application number: CN202080037894.5A
Authority: CN
Inventors: 沃尔夫冈·斯托耶科尔
Original assignee: Lisa Draexlmaier GmbH
Current assignee: Lisa Draexlmaier GmbH
Priority date: 2019-05-20
Filing date: 2020-04-09
Publication date: 2022-01-07
Anticipated expiration: 2040-04-09
Also published as: EP3972751A1; CN113905833B; WO2020233903A1; DE102019113285A1

Abstract

The invention relates to a method for cyclically controlling a punch (102) of a punching tool (100), wherein during a cycle of the press tool (100) a linear opening movement (122) of the press tool (100) is converted into a rotational movement (124) by using a transmission (118) of the press tool (100), and the angular position (128) of the cam (130) of the camshaft (120) of the punching tool (100) is changed in angular steps (152), wherein, in a closing movement (114) following an opening movement (122) of the punching tool (100) in a cycle, sensing an angular position (128) of a cam (130) adjusted during the opening movement (122) by using a sensing device (126) of the punching tool (100), wherein a working movement of the ram (102) driven by the closing movement (114) is carried out as a function of the sensed angular position (128). The invention further relates to a correspondingly designed press tool.

Description

Method for cyclically controlling a punch of a punching tool and punching tool

Technical Field

The invention relates to a method for cyclically controlling a punch of a punching tool and a punching tool with at least one controllable punch.

Background

In the case of a punching tool for producing stampings with slightly different punching geometries, certain punches of the punching tool can be activated or deactivated by an externally controlled actuator in the punching tool, depending on the version variant just produced. The controlled ram then executes or does not execute a working movement during the closing movement of the punching tool. Thus, different stamping geometries can be manufactured in the same stamping tool. For example, the actuators may be controlled by electrical, hydraulic or pneumatic signals.

Disclosure of Invention

The object of the invention is therefore to provide a punching tool with at least one controllable punch and a method for cyclically controlling the punch of a punching tool by using measures which are as simple as possible in terms of construction.

This technical problem is solved by the subject matter of the independent claims. Advantageous developments of the invention are given in the dependent claims, the description and the drawings. In particular, independent claims of one claim category can also be extended analogously to dependent claims of another claim category.

The invention relates to a method for cyclically controlling a punch of a punching tool, wherein, during a cycle of the punching tool, a linear opening movement of the punching tool is converted into a rotational movement by using a transmission device of the punching tool, and an angular position of a cam of a camshaft of the punching tool is changed in angular steps, wherein, during a closing movement of the punching tool following the opening movement in the cycle, an angular position of the cam adjusted during the opening movement is sensed by using a sensing device of the punching tool, wherein a working movement of the punch driven by the closing movement is carried out depending on the sensed angular position.

Furthermore, a punching tool with at least one controllable punch is proposed, wherein the punching tool has a transmission for converting a linear opening movement of the punching tool into a rotational movement of a camshaft of the punching tool and a sensing device for sensing an angular position of a cam of the camshaft during a closing movement of the punching tool, wherein the transmission is designed to rotate the camshaft with the cam in angular steps by using the opening movement, and the sensing device is designed to control an operating movement of the punch driven by the closing movement as a function of the sensed angular position of the cam.

The stamping may be made of a continuous material, for example of sheet metal, unwound from a roll. At the beginning of the production process for producing the stamping, the continuous material may already have a width which approximates the width of the stamping in order to achieve a high material utilization. The continuous material can be introduced into a stamping tool for producing stamping parts on the input side. On the output side of the stamping tool, the stampings and manufacturing residues of the continuous material can be removed from the stamping tool.

The press tool has an upper tool part and a lower tool part movable relative to the upper tool part. The upper tool part and the lower tool part may be secured to opposed tool receivers of the press. The web is guided between an upper tool part and a lower tool part. The upper tool part and/or the lower tool part may be driven. The upper tool part and the lower tool part may be guided relative to each other by means of a linear guide. The press tool is cyclically opened and closed by the press machine. For example, the punch tool may be opened and closed hundreds of times per minute.

The press tool may have successive manufacturing locations through which the continuous material is circulated from the input side. During the cycle the punch is opened and the web is transported to the next manufacturing location and the punch is closed again. The manufacturing locations are formed in the upper and lower tool parts, respectively. In each manufacturing position, by using a punch supported in the stamping tool, voids or contours, indentations and/or bends can be introduced into the continuous material when the stamping tool is closed. The punches may be arranged in the upper tool part as well as in the lower tool part. The opposing piece of the punch may be arranged coaxially with the punch in the other tool part.

The punch may be a cutting punch for making a void or a contour, a pressing punch for making an indentation and/or a bending punch for making a bend. The punch may also have a combined function. The punch can be driven to perform a working movement by a closing movement of the punching tool. In this case, the web can first be clamped between the upper tool part and the lower tool part by a closing movement. Subsequently, the punch receiving part of the spring-loaded punching tool coupled with the punch can be moved further through the punching machine and the pressing punch performs a working movement of the punch through, against and/or against the continuous material from its bearing position in the upper and/or lower tool part. The working movement of the punch may be less than the closing movement of the punching tool.

The transmission may be coupled with the upper tool part and the lower tool part to receive the linear opening movement thereof. The transmission ratio of the transmission may be defined as the ratio between the length of the opening movement and the angle of rotation of the rotating movement. Since the opening movement is the same in each cycle, the angle of rotation is always the same. The rotational angle can be converted into angular steps of the camshaft in a further transmission ratio. The camshaft must be stationary during the closing movement. At a constant transmission ratio, the camshaft continues to rotate by the same angular step with each identical opening movement.

The cam may be a protrusion on the camshaft. The cam may protrude radially from the camshaft. During the closing movement, it can be sensed whether the cam is arranged in the sensed angular position. The sensing device may be movable relative to the camshaft. The sensing device may be moved by the closing motion to sense the angular position. When the cam is arranged in an angular position, contact occurs between the cam and the sensing device. The punch receptacle is thereby coupled to the closing movement and can drive the working movement of the punch by means of the closing movement.

The angular position may be sensed by a sensing tab of a ram receptacle coupled with the ram. The working movement can be performed when the cam bears against the sensing cam during the closing movement. The sensing means may be designed as a sensing bump. The sensing bump may be a protrusion of the punch receiving portion. The sensing bumps may be fixedly disposed on the punch receiving portion. The cam may have a contact surface which, when the cam is arranged in the sensed angular position, meets a corresponding impact face of the sensing bump. The working movement can be released when the cam pushes against the sensing cam.

When the sensing cam is sunk into the cam gap of the camshaft, the working movement cannot be performed. The cam gap may be a void or free space between two sides of the cam of the camshaft. If the camshaft has only one cam, the cam gap between two opposite sides of the same cam can extend over the remaining circumference of the camshaft. If the sensing bump does not abut the cam due to the cam being disposed at another angular position, no contact between the cam and the sensing bump results. The working movement is not released.

The working motion may be transmitted from the cam to the sensing device. The punch may be driven by the sensing device. When the cam is oriented to the sensing device, the contact surface of the cam may be oriented transverse to the direction of the closing movement. The impact surface of the sensing device may also be oriented transversely to the direction of the closing movement. The force for driving the punch may be transmitted through the contact surface and the impact surface.

The stroke of the working movement may be determined by the height of the cam. The stroke of the working movement can be started when the cam is in contact with the sensing means, i.e. when the contact surface is against the striking surface. The height of the cam can be matched to the punch to be operated. The camshaft may have cams of different heights to provide different strokes in different cycles for the same punch.

The number of cycles in which the press tool does not execute a working movement between two cycles of executing a working movement can be influenced by the transmission ratio of the transmission. The number may also be affected by the size of the cam gap between the two cam flanks. The transmission ratio can be adjusted as desired. The number of cams on the camshaft can also be adjusted.

For adjusting the transmission ratio, the transmission device can have a rotatably mounted, exchangeable lever. The free end of the rod may be coupled to an opposite side of the press tool. The transmission ratio of the transmission may be affected by the length of the rod. The lever may be rotatably supported within the upper tool part or the lower tool part. The opposite side may be formed by the lower tool part or the upper tool part, respectively. The rod may be driven by an element rigidly connected to the opposite side. A bearing with two degrees of freedom may be arranged on the free end of the rod to convert a linear opening movement of the element into an arc-shaped movement of the rod. The bearing may be a rotation-sliding hinge. For example, a slot or slit in the rod may compensate for rod roundness errors. The rods may also be driven by separate coupling means. The coupling means may be formed by separate rods rotatably supported on opposite sides. While the connection between the rod and the coupling device may have a degree of freedom, i.e. be designed as a pure rotational hinge.

The transmission may have at least one replaceable gear pair. The transmission ratio of the transmission may be influenced by the transmission ratio of the gear pair. One gear of the gear pair may be coupled with the camshaft, while the other gear may be arranged between the camshaft and the drive of the transmission.

The transmission has a flywheel for decoupling the opening movement from the closing movement. The flywheel can only transmit a rotational movement when the rotational movement occurs in the blocking direction of the flywheel. The blocking direction coincides with the opening movement. The rotational movement is thereby transmitted to the camshaft only during the opening movement. The rotational movement occurs in one direction only. The flywheel can be arranged at different positions of the transmission. In particular, the flywheel may be arranged between a lever of the transmission and an adjacent gear pair of the transmission.

The flywheel may be a ratchet flywheel. The angular step of the camshaft performed per opening movement can be influenced by the angle between the detent positions of the ratchet wheel. The ratchet wheel can only transmit a rotational movement when at least one ratchet of the ratchet wheel engages into a latching position of the ratchet wheel. The ratchet wheel can only transmit part of the rotational movement of the drive side to the driven side of the ratchet wheel. The remainder of the rotational movement of the drive side is a slip. The angular step on the drive side of the ratchet wheel, which is produced by the opening movement, is thus greater than the angular step transmitted from the output side to the camshaft.

The camshaft may have at least one exchangeable cam disk. At least one cam may be arranged on the cam disc. The cam disc may be a ring having at least one cam on its outer side. Different cam disks may have different numbers of the same type of cam. The cams may be distributed at regular intervals on the circumference of the cam plate. The inner side of the cam disc may be matched to the diameter of the shaft of the camshaft. The cam disk can be connected to the shaft in a rotationally fixed manner and can be released again. The cam disc may be exchanged to adjust the number of cycles in which no working movement is performed.

The punching tool may have a brake which is designed to keep the angular position of the camshaft constant during the closing movement. The brake may be a friction brake. A minimum torque may be required to overcome the friction of the brake. The minimum torque may be greater than the flywheel drag torque against the blocking direction. The brake can also be designed as another flywheel. At least the direction of rotation of the camshaft is thereby clearly defined.

The punching tool may have at least one further camshaft. Furthermore, the transmission can be designed to rotate the further camshaft in synchronism with this camshaft in angular steps by using the opening movement. The further camshaft may rotate synchronously with the camshaft during the opening movement. The further camshaft can be coupled to the camshaft, for example, via a gear pair with a transmission ratio of one. The further camshaft may have a different direction of rotation than this camshaft. The additional camshaft may be sensed by a separate sensing device.

Drawings

Advantageous embodiments of the invention are explained below by referring to the drawings. The figures are as follows:

fig. 1 shows a cross-sectional illustration of a press tool opened during a cycle according to an embodiment;

FIG. 2 shows a cross-sectional illustration of a press tool closed during a cycle, according to an embodiment;

FIG. 3 shows a cross-sectional illustration of a press tool opened during a subsequent cycle, in accordance with an embodiment; and

fig. 4 shows a cross-sectional illustration of a press tool closed during a subsequent cycle according to an embodiment.

The drawings are merely schematic representations and are intended to be illustrative of the invention. Identical or functionally identical elements have the same reference numerals throughout

Detailed Description

For easier understanding, reference numerals of fig. 1 to 4 are retained in the following description as references.

Fig. 1 shows a cross-sectional illustration of a press tool 100 opened during a cycle according to an embodiment. The punching tool 100 is shown here in a sectional view by means of at least one controllable punch 102 of the punching tool 100. The press tool 100 has a driven upper tool part 104 and a fixed lower tool part 106. Within the lower tool part 106, a die, which is an opposing piece 108 of the punch 102, is arranged coaxially with the punch 102. The upper tool part 104 is supported linearly movably on the lower tool part 106 by means of guide posts. The upper tool part 104 and the lower tool part 106 are coupled in operation with a punch, not shown here. The punch moves the upper tool portion 104 up and down. The upper tool part 104 may move up and down hundreds of times per minute.

The upper tool part 104 is multi-piece. The hold-down device 110 of the upper tool part 104 is arranged between the lower tool part 106 and a back plate 112 of the upper tool part 104. The punch 102 is movably supported in the pressing device 110. During the closing movement 114, the holding-down device 110 leads the back plate 112 and rests on the stamping 116 to be produced. After the pressing device 110 has been placed against the stamp 116, the back plate 112 performs a relative movement with respect to the pressing device 110 as a result of the continuous closing movement 114. By the relative movement, the distance between the hold-down device 110 and the back plate 112 is reduced. The relative motion may be at least partially transmitted to the punch 102. When the relative movement is transmitted to the punch 102, the punch 102 is removed from the pressing device 110 and the stamping 116 is machined.

The stamping 116 is here made from a single sheet. The punch 102 may be a cutting punch and is designed to punch out a void or contour from the sheet material. While the counter-piece may have a through-hole for the produced punching scrap. The punch 102 can also be a bending punch and is designed to bend a partial region of the stamping 116 out of the plane of the sheet metal. The bending punch may also have a cutting edge and cut the contour of the local area into the sheet material before bending. While the counter piece 108 may have a void for a partial area to be bent. The counter piece 108 may also have a spring-loaded counter holder. The counter piece 108 can also have a curved edge which specifies a bending radius for the partial region to be bent. The punch 102 can likewise be a pressing punch and is designed to introduce an impression into the pressed stamping 116. The counter piece 108 may have a negative profile of the indentation. The bending punch may also have an indentation profile, for example to press a rib that reinforces the bend.

A transmission 118 and at least one camshaft 120 are arranged on the back plate 112 of the upper tool part 104. The transmission 118 converts a linear opening movement 122 of the upper tool part 104 along the guide post into a rotational movement 124 of the camshaft 120.

A sensing device 126 for sensing the angular position 128 of a cam 130 of the camshaft 120 is movably supported on the pressing device 110. Sensing device 126 is coupled with ram 102. The sensing device 126 is disposed between the compression device 110 and the backing plate 112. Here, the upper tool part 104 is illustrated at top dead center. The sensing device 126 is spaced apart from the camshaft 120.

The transmission 118 has: a lever 134 coupled to the lower tool part 106 by a follower 132, a gear pair 136 with a defined gear ratio, and a flywheel 138 arranged between the lever 134 and the gear pair 136. The lever 134, the flywheel 138 and the first gear 140 of the gear pair 136 are arranged on a common axis of rotation and are rotatably supported within the upper tool part 104. The flywheel 138 is designed as a ratchet flywheel. The lever 134 is connected in a rotationally fixed manner to a support for a catch pawl 142 of the flywheel 138. The catch pawl 142 engages into a ratchet wheel 144 of the freewheel 138 in a defined position. The latch pawl 142 is designed to carry the ratchet wheel 144 in only one rotational direction (counterclockwise in the illustration). The ratchet wheel 144 is connected in a rotationally fixed manner to the first gearwheel 140 of the gearwheel pair 136. The second gearwheel 146 of the gearwheel pair 136 is coupled in a rotationally fixed manner to the camshaft 120 and is rotatably mounted in the upper tool part 104 on a common rotational axis with the camshaft 120. The rotational axes of the second gear 146 and the camshaft 120 are aligned parallel to the rotational axes of the lever 134 of the flywheel 138 and the first gear 140.

In the opening movement 122 before the illustrated top dead center, the lever 134 has been rotated (in the counterclockwise direction in the illustration) by the follower 132 by a first angular step 148 into the illustrated position of the lever 134. The detent pawl 142 has carried the ratchet wheel 144 and rotated a second angular step 150. Due to the defined engagement position of the detent pawl 142, the second angular step 150 is smaller than or equal to the first angular step 148. Gear pair 136 has converted, via its transmission ratio, a second angular step 150 into an angular step 152 of camshaft 120. Because first gear 140 has a greater number of teeth than second gear 146, angular step 152 of camshaft 120 is greater than second angular step 150. With the previous angular step 152, the cam 130 is rotated into the illustrated angular position 128.

In one embodiment, the first gear 140 and/or the second gear 146 may be replaced with other gears having a greater or lesser number of teeth. The transmission ratio can be adjusted by other gears.

In one embodiment, the press tool 100 has a second cam shaft 120. The second camshaft 120 is connected in a rotationally fixed manner to the third gear 154. The third gear 154 is engaged with the second gear 146, and thus the second camshaft 120 has a rotational direction opposite to that of the first camshaft 120. The second gear 146 and the third gear 154 have the same number of teeth. Thereby, the second camshaft 120 is rotated at the same angular step as the first camshaft 120.

Fig. 2 shows a cross-sectional view of the press tool 100 closed during the cycle in fig. 1, according to an embodiment. The stamping tool 100 substantially corresponds to the stamping tool in fig. 1. The upper tool part 104 has fully performed the closing movement 114. The upper tool portion 104 is illustrated here at bottom dead center. The pressing device 110 has rested on the stamping 116 and the back plate 112 has performed a relative movement 200 with respect to the pressing device 110. Because the angular position 128 of the cam 130 is held constant by the detent 202 of the transmission 118, the cam 130 is oriented in the illustrated angular position 128 such that the cam 130 bears against the sensing tab 204 of the sensing device 126. By the contact between the cam 130 and the sensing cam 204, part of the relative movement 200 has been transferred to the punch 102, and the punch 102 has performed its working movement 206 and has machined the stamping 116. The sensing bump 204 is here part of the rear punch receptacle of the punching tool 100.

The lever 134 has been rotated (clockwise in the figure) by the follower 132 through a reverse first angular step 148. However, because the flywheel 138 is sliding in this direction, the reverse first angular step 148 is not transferred to the first gear 140. Here, the brake 202 also acts on the first gearwheel 140 and prevents the first gearwheel 140 from moving due to a possible drag torque of the flywheel 138.

Fig. 3 shows a cross-sectional illustration of the press tool 100 opened during a subsequent cycle according to an embodiment. The pressing tool 100 here corresponds substantially to the pressing tool in fig. 1 and 2. The upper tool part 104 has fully performed the opening movement 122. The upper tool part 104 is here at bottom dead center as illustrated in fig. 1. Here, the holding-down device 110 has been lifted from the stamping 116, and the punch 102 is retracted again into the holding-down device 110.

In the illustrated opening movement 122 before top dead center, the lever 134 has been rotated (in a counterclockwise direction in the illustration) by the follower 132 by an updated first angular step 148 to its illustrated position. The detent pawl 142 has carried the ratchet wheel 144 and rotated it through the updated second angular step 150. Due to the defined engagement position of the detent pawl 142, the updated second angular step 150 is less than or equal to the updated first angular step 148. Gear pair 136 converts the updated second angular step 150 into an updated angular step 152 of camshaft 120 via its gear ratio. Because the number of teeth of the first gear 140 is greater than the number of teeth of the second gear 146, the updated angular step 152 of the camshaft 120 is greater than the updated second angular step 150. Cam 130 has been rotated from angular position 128 to second angular position 300 by the previous, updated angular step 152. Due to the updated angular step 152, the cam 130 is no longer opposite the sense bump 204.

In one embodiment, the first gear 140 and/or the second gear 146 may be replaced with additional gears having a greater or lesser number of teeth. The transmission ratio can be adjusted by means of further gears. The angular step 152 is also changed by the changed transmission ratio.

In one embodiment, the rod 134 may be replaced with another rod of a different length. The first angular step 148 may be adjusted by different lengths of the rod 134.

Fig. 4 shows a cross-sectional illustration of the press tool 100 closed during a subsequent cycle in fig. 3, in accordance with an embodiment. The stamping tool 100 substantially corresponds to the stamping tool in fig. 3. The upper tool part 104 has fully performed the closing movement 114. The upper tool portion 104 is again illustrated here at bottom dead center. Here, the holding-down device 110 has been illustrated as resting again on the stamping 116, and the back plate 112 has again performed a relative movement 200 relative to the holding-down device 110. Since the second angular position 300 of the cam 130 is kept constant by the brake 202 of the transmission 118, the sensing cam 204 sinks into the cam gap 400 of the camshaft 120. The relative motion 200 is not transmitted to the punch 102.

In one embodiment, the camshaft 120 is implemented in two pieces. A replaceable cam plate 402 is fixed on the central shaft. The cam disc 402 depicted here has four cams 130. To accommodate the idle strokes of the lost motion 206, the cam disk 402 may be replaced with another cam disk with more or fewer cams 130. The number of cams 130 affects the length of the cam gap. The greater the cam clearance, the more successive cycles the sensing bump 204 sinks into the cam clearance 402.

In other words, the method proposed herein allows for cyclic control during the stamping process.

Cycle control is understood to mean the linkage of the (cutting) punches in a regular cycle, i.e. for example only at every second or every third punching stroke. One particular application of the method proposed herein is for the linkage of laminated contact punch stacks. Tool failures may be reduced by the proposed cyclic control compared to other types of linkages. Furthermore, an increase in speed (stroke/minute) can also be achieved by mechanical linkage of the cutting punches. The mechanical linkage reduces unused and therefore unsaved spare parts, such as rotating magnets, plugs and valves, which may fail due to chatter during the stamping process.

The up-and-down movement of the automatic punch is transmitted to the ratchet wheel through the linkage of the rod. This transmits the rotational movement to the camshaft, if necessary, via a transmission. Two coupled camshafts can also be used for high demands on accuracy. Depending on the position of the camshaft(s), the punch is actuated when the tool is closed or the cam drive does not actuate the punch.

So far, the linkage of the punch is done by pneumatic means or at least one rotating magnet. The pneumatic device is very slow here, since only a low lifting speed can be achieved. Due to the constant chatter, the rotary magnet may fail mechanically, or the plug connection may fail due to a moving connection in the upper tool part. Troubleshooting is thus often made difficult because of the combination of electronic and mechanical devices. Faults sometimes occur only in continuous operation, which makes fault analysis difficult.

The linkage proposed here is directly applicable to a family of layered contact products having millions of parts per week. The linkage proposed here achieves an increase in the hoisting speed and a reduction in the tool downtime, as well as a simplified error analysis. The tool operates without any special control and can therefore be used for different automatic presses. Fewer spare parts are required.

During the punch stroke with punch actuation, the ratchet wheel is rotated to a defined position in the top dead center (OT) of the tool by a catch pawl (pawls) connected to the linkage. The camshaft(s) are rotated through the geared connection to a first position in which the cam(s) are oriented vertically downward. The punch cuts through the material when the tool is closed, as the punch is actuated by the cam(s) of the camshaft(s).

When the tool is closed, the linkage lever/latch pawl unit rotates to the next position. A spring-loaded brake on the ratchet prevents the ratchet and camshaft(s) from rotating. When the tool is opened to the top dead center (OT) next time, the linkage lever/latch pawl unit brings the ratchet wheel to the next position, and the cam shaft is correspondingly rotated to the next position through the gear connection. During the subsequent closing process, the camshaft with its recess accordingly protrudes beyond the cutting punch, so that the cutting punch is not actuated and no cutting takes place. The process is repeated continuously so that a defined number of working strokes and idle strokes are always performed. The ratio of the working stroke to the idle stroke is determined by the rotation angle of the linkage rod, the transmission ratio, the number of the locking parts in the ratchet wheel and the design of the cam shaft. In the illustrated example, one work stroke is performed and then two idle strokes are performed as a continuous cycle.

Upon opening, the catch pawl rotates the ratchet and the camshaft to a defined position. When closed, the linkage rod places the latch pawl in the next position. Here, the camshaft remains engaged and the cutting punch cuts the material. Upon subsequent opening, the latch pawl rotates the ratchet and cam shaft one position further. When subsequently closed, the linkage rod places the catch pawl in the next position. The cam shaft is not engaged and the cutting punch does not cut the material.

Since the apparatus and methods described in detail above are exemplary embodiments, those skilled in the art will generally appreciate that they can make numerous modifications thereto without departing from the scope of the present invention. In particular, the mechanical arrangements and the proportions of the individual elements to one another have been chosen merely as examples.

List of reference numerals

100 punching tool

102 punch

104 upper tool part

106 lower tool part

108 opposite piece

110 hold-down device

112 backboard

114 closing movement

116 stamping part

118 driving device

120 camshaft

122 opening movement

124 camshaft rotation motion

126 sensing device

128 angular position

130 cam

132 follower

134 pole

136 gear pair

138 flywheel

140 first gear

142 latch pawl

144 ratchet wheel

146 second gear

148 first angular step

150 second angular step

152 angular steps

154 third gear

200 relative movement

202 brake

204 sense bump

206 working movement

300 second angular position

400 cam clearance

402 cam disc

Claims

1. A method for cyclically controlling a punch (102) of a punching tool (100), wherein during a cycle of the press tool (100) a linear opening movement (122) of the press tool (100) is converted into a rotational movement (124) by using a transmission (118) of the press tool (100), and changing the angular position (128) of a cam (130) of a camshaft (120) of the punching tool (100) in angular steps (152), wherein, during a closing movement (114) following an opening movement (122) of the punching tool (100) in a cycle, sensing an angular position (128) of the cam (130) adjusted during the opening movement (122) by using a sensing device (126) of the punching tool (100), wherein a working movement (206) of the punch (102) driven by the closing movement (114) is performed as a function of the sensed angular position (128).

2. Method according to claim 1, wherein the angular position (128) is sensed by a sensing cam (204) of a punch receiving portion coupled with the punch (102), wherein the working movement (206) is performed when the cam (130) bears against the sensing cam (204) upon the closing movement (114).

3. The method of claim 2, wherein the working motion (206) is not performed when the sense bump (204) sinks into a cam clearance (400) of the camshaft (120).

4. Method according to any one of the preceding claims, wherein the working motion (206) is transmitted from the cam (130) to the sensing means (126) and the punch (102) is driven by the sensing means (126).

5. The method according to claim 4, wherein the stroke of the working motion (206) is determined by the height of the cam (130).

6. Method according to any of the preceding claims, wherein the number of cycles in which the press tool (100) does not execute a working movement (206) between executing two cycles of a working movement (206) is influenced by the transmission ratio of the transmission (118).

7. The method according to any of the preceding claims, wherein the number of cycles in which the press tool (100) does not perform a working motion (206) between performing two cycles of a working motion (206) is influenced by the size of the cam gap (400) between two cam flanks.

8. Punching tool (100) with at least one controlled punch (100), wherein the punching tool (100) has: -a transmission device (118) for converting a linear opening movement (122) of the punching tool (100) into a rotational movement (124) of a camshaft (120) of the punching tool (100), and-a sensing device (126) for sensing an angular position (128) of a cam (130) of the camshaft (120) during a closing movement (114) of the punching tool (100), wherein the transmission device (118) is designed to rotate the camshaft (120) with the cam (130) in angular steps (152) by using the opening movement (122), and the sensing device (126) is designed to control a working movement (206) of the punch (102) driven by the closing movement (114) depending on the sensed angular position (128) of the cam (130).

9. The press tool (100) according to claim 8, wherein the transmission (118) has a flywheel (138) for decoupling the opening movement (122) from the closing movement (114).

10. The punching tool (100) according to claim 9, wherein the flyweight (138) is a ratchet flyweight, wherein the angular step (152) performed by the camshaft (120) per opening movement (122) is influenced by the angle between the ratchet flyweight detent positions.

11. A press tool (100) according to any one of the preceding claims, with a brake (202) designed to keep the angular position (128) of the camshaft (120) constant during the closing movement (114).

12. A press tool (100) according to any of the preceding claims, wherein the transmission (118) has a rotatably supported exchangeable lever (134), wherein a free end of the lever (134) is coupled with an opposite side of the press tool (100), wherein a transmission ratio of the transmission (118) is influenced by the length of the lever (134).

13. A press tool (100) according to any of the preceding claims, wherein the transmission (118) has at least one exchangeable gear pair, wherein the transmission ratio of the transmission (118) is influenced by the transmission ratio of the gear pair.

14. The punching tool (100) according to any of the preceding claims, wherein the camshaft (120) has at least one exchangeable cam disc (402), wherein the at least one cam (130) is arranged on the cam disc (402).

15. Press tool (100) according to any one of the preceding claims, wherein the press tool is provided with at least one further camshaft (120), wherein the transmission (118) is further designed to rotate the further camshaft (120) in angular steps (152) synchronously with the camshaft (120) by using the opening movement (122).