Hand press for pressing, joining or assembling workpieces

Abstract

Hand press for pressing, joining or assembling workpieces, comprising a base frame (2), wherein the base frame (2) has a press table (3) for placing a workpiece, wherein the base frame (2) has a drive unit (4) for driving a quill (5) in the direction of the workpiece, wherein a press ram (6) is provided which is movable relative to the sleeve (5) in the direction of the workpiece, so that further movement of the sleeve (5), after the press ram (6) touches the workpiece, leads to a reduction of the distance (7) between the press ram (6) and the sleeve (5), wherein a first sensor (8) is provided which, when the sleeve (5) moves further in the direction of the workpiece after the press ram (6) touches the workpiece, emits a first signal when a predetermined distance (9) between the sleeve (5) and the press table (3) is undershot, wherein the sleeve (5) has a fixing device (10) which fixes the press ram (6) against the sleeve (5) at the first signal, wherein a path limiter (11) is provided which, upon the first signal, limits the pressing path of the sleeve (5) in the direction of the workpiece to a predetermined pressing path (12).

Description

[0001] The invention relates to a hand press for pressing, joining or assembling workpieces of different heights.

[0002] In all pressing, joining, and assembly processes, tolerances exist between the individual workpieces. The workpieces can be, for example, plugs, housing covers, filters, pins, snap rings, and all kinds of assembly parts. Up to approximately 90% of these workpieces are assembled or pressed in using simple presses such as toggle presses and rack and pinion presses. The main disadvantage of these presses is that the pressing distance can only be roughly adjusted using a simple adjusting screw. Tolerance compensation for the different heights of the workpieces is not possible and can only be roughly adjusted by using device holders of different heights. This is not sufficient to guarantee the quality of the cohesion of the workpieces, because the tolerances of the individual workpieces are not taken into account in this way.

[0003] To ensure high-quality and safe assembly, spindle-driven high-tech presses are available, which feature complex and expensive sensor technology. Disadvantages include longer assembly times, larger work space, safety features, and complex measuring systems, such as distance measurement, pressure measurement, and current consumption measurement.

[0004] The invention is based on the object of providing a hand press which ensures a high quality of cohesion of workpieces with different heights at low cost.

[0005] The object of the invention is achieved by the subject matter of claim 1. The subject matter of claim 1 is a hand press for pressing, joining, or assembling workpieces, comprising a base frame, wherein the base frame has a press table for placing a workpiece, wherein the base frame has a drive unit for driving a sleeve in the direction of the workpiece, wherein a press ram is provided which is movable relative to the sleeve in the direction of the workpiece, so that further movement of the sleeve, after the press ram has touched the workpiece, leads to a reduction in the distance between the press ram and the sleeve, wherein a first sensor is provided which, when the sleeve is moved further in the direction of the workpiece after the press ram has touched the workpiece, emits a first signal when the distance between the sleeve and the press table falls below a predetermined distance, wherein the sleeve has a fixing device,which fixes the press ram against the sleeve at the first signal, wherein a travel limiter is provided which limits the pressing travel of the sleeve in the direction of the workpiece to a predetermined pressing travel at the first signal.

[0006] The object of the invention is achieved by the fact that the press ram is pressed onto the workpiece only after the press ram has touched the workpiece. In this way, the predetermined pressing distance always remains the same, even if the height of the workpieces to be pressed changes. Since the pressing distance can be limited to the predetermined pressing distance using simple mechanical means, the hand press according to the invention is easy to manufacture and therefore cost-effective.

[0007] According to a favorable variant, the path limiter is designed as a body that can be removed from the pressing path, the height of which defines the predetermined pressing path. The body can be moved pneumatically, hydraulically, or electrically.

[0008] According to a favorable embodiment, the first sensor has a micrometer screw, by means of which the predetermined distance between the sleeve and the press table can be adjusted. Using a micrometer screw, the predetermined distance between the sleeve and the press table can be adjusted with micrometer precision.

[0009] According to a favorable embodiment, the drive unit is a mechanical, an electrical, a pneumatic or a hydraulic drive unit.

[0010] According to a favorable embodiment, the fixing device fixes the press ram against the quill mechanically, electrically, pneumatically or hydraulically.

[0011] According to an advantageous embodiment, the fixing device has at least one clamping jaw, by means of which the press ram is fixed against the sleeve. The clamping jaws can be driven mechanically, electrically, pneumatically, or hydraulically.

[0012] According to an advantageous development, a spring element is arranged between the press ram and the sleeve, which maximizes the distance between the press ram and the sleeve before the press ram touches the workpiece. The spring element ensures that the press ram is returned to its starting position after the fixing device is released. The spring element can be mechanical, hydraulic, pneumatic, or electrical.

[0013] According to an advantageous development, a second sensor is provided which, when the sleeve is driven in the opposite direction to the workpiece, emits a second signal when the predetermined distance between the sleeve and the press table is exceeded. Upon receipt of the second signal, the locking device releases the locking between the sleeve and the press ram, and upon receipt of the second signal, the travel limiter removes the limitation of the pressing travel to the predetermined travel of the sleeve in the direction of the workpiece. The second signal from the second sensor returns both the locking device and the travel limiter to their initial positions. This allows the pressing process to begin again.

[0014] The object of the invention is also achieved by means of a method according to the invention. The subject matter of the method according to the invention is a method for pressing a workpiece using a hand press, comprising a base frame with a press table on which a workpiece is placed, and with a drive unit for driving a sleeve toward the workpiece, wherein a press ram is provided which is movable relative to the sleeve and points toward the workpiece, comprising the method steps: driving the sleeve toward the workpiece until the press ram touches the workpiece, further moving the sleeve toward the workpiece so that the press ram reduces its distance from the sleeve, transmitting a first signal when a predetermined distance is undershot between the sleeve and the press table, fixing the press ram relative to the sleeve upon transmission of the first signal,Limiting the pressing distance of the sleeve from the predetermined distance at which the first signal is transmitted to a predetermined pressing distance, moving the sleeve further in the direction of the workpiece until the predetermined pressing distance has been covered and the workpiece is pressed in.,

[0015] According to an advantageous development, when the sleeve is driven in the opposite direction to the workpiece, a second signal is emitted when the predetermined distance between the sleeve and the press table is exceeded. Upon the emission of the second signal, the fixation between the press ram and the press table is released, and the limitation of the pressing path of the sleeve in the direction of the workpiece to a predetermined pressing path is removed. The second signal from the second sensor returns both the fixing device and the path limiter to their initial positions. This allows the pressing process to begin again.

[0016] The invention is explained in more detail with reference to the following drawings. It shows: Fig. 1: a side view of a hand press according to the invention, Fig. 2: a longitudinal section of a fixing device, Fig. 3: an enlargement of the side view according to Fig. 1 from a distance limiter where a body obstructs the pressing process, and Fig. 4: an enlargement of the side view according to Fig. 1 from a section limiter where the body is pushed away so that the pressing section is free.

[0017] Fig. 1 shows a side view of a hand press 1 according to the invention for pressing, joining, or assembling workpieces. The hand press 1 comprises an L-shaped base frame 2. The base frame 2 has a press table 3 for placing workpieces, wherein the press table 3 is arranged on a base (not shown). Furthermore, the base frame 2 has a tripod-shaped part 18 that projects vertically perpendicular to the press table 3. Workpieces (not shown) can be placed on the press table 3.

[0018] At an end of the stand-shaped part 18 opposite the press table 3, a press head 19 is arranged, which has a hollow cylindrical passage 28 pointing in the direction of the press table 3. A cylindrical sleeve 5 is arranged in the passage 28 and is movably mounted in the direction of the press table 3.

[0019] A holding plate 20 is arranged at an end of the sleeve 5 opposite the press table 3. A drive unit 4 is provided, which moves the holding plate 20 and thus the sleeve 5 in the direction of the press table 3, wherein the drive unit 4 is designed as a lever 21.

[0020] A fixing device 10 is arranged at an end of the sleeve 5 pointing toward the press table 3. The fixing device 10 has a press ram 6 pointing toward the press table 3. The fixing device 10 is arranged between the sleeve 5 and the press ram 6, so that the press ram 6 is a straight continuation of the sleeve 5 toward the press table 3. A first sensor 8 and a micrometer screw 14 are arranged on the holding plate 20.

[0021] The fixing device 10 has a second sensor 17, which is similar in structure to the first sensor 8 and points in a direction opposite to the first sensor 8, toward the press head 19. If the lever 21 is actuated such that the sleeve 5 and thus the press ram 6 are moved in a direction opposite to the workpiece, the second sensor 17 generates a second signal when a predetermined distance 27 between the fixing device 10 and the press head 19 is exceeded. Falling below the predetermined distance 27 between the fixing device 10 and the press head 19 corresponds to exceeding the predetermined distance 9 between the sleeve 5 and the press table 6.

[0022] Fig. Figure 2 shows a longitudinal section of the fixing device 10. A spring element 16 is arranged between the sleeve 5 and the press ram 6, so that the press ram 6 is spring-loaded against the sleeve 5. In this way, the distance 7 between the press ram 6 and the sleeve 5 is increased to a stop at the beginning of the pressing process. The fixing device 10 is attached to an end face of the sleeve 5 facing toward the workpiece, with the press ram 6 passing through the fixing device 10.

[0023] Two cylindrical clamping jaws 15 are arranged in the fixing device 10, each of which is arranged perpendicular to the press ram 6 and which do not touch the press ram 6 at the beginning of the pressing process. The clamping jaws 15 are each driven by a clamping cylinder 22. When the clamping cylinder 22 is activated, the clamping jaws 15 are pressed firmly against the press ram 6, so that the press ram 6 is fixed and the distance 7 between the press ram 6 and the sleeve 5 can no longer be changed. In this position, the press ram 6 can be pressed onto the workpiece. If the clamping cylinder 22 is deactivated, the clamping jaws 15 are released from the press ram 6 and the spring element 16 springs the press ram 6 in the opposite direction of the sleeve 5 up to the stop, so that the distance 7 between the press ram 6 and the sleeve 5 is once again maximum.

[0024] Fig. Figure 3 shows a side view of a travel limiter 11. The travel limiter 11 is arranged on the end face of the upwardly projecting end of the tripod-shaped part 18 of the base frame 2. The travel limiter 11 is designed as a slider 24. The slider 24 comprises a rail 25 in which a body 13 is movably arranged. A drive 23 moves the body 13 back and forth in the rail 25.

[0025] The first sensor 8 and the micrometer screw 14 both point in the direction of the slide 24. The micrometer screw 14 is used to set a predetermined distance 26 between the holding plate 20 and the body 13 of the slide 24, whereby this distance 26 defines the predetermined distance 9 between the sleeve 5 and the press table 3. If the first sensor 8 touches the body 13, the first sensor 8 generates a first signal and sends the first signal to the fixing device 10, whereupon the press ram 6 is fixed against the sleeve 5. Now, with a further actuation of the lever 21, the press ram 6 can be pressed against the workpiece. The first signal of the first sensor 8 is also sent to the drive 23 of the slide 24. The drive 23 then pushes the body 13 away (see Fig. 4), so that the body 13 no longer stands in the way of the first sensor 8.

[0026] Fig. Figure 4 shows a side view of a travel limiter 11, in which the body 13 is moved away by the drive 23, so that the first sensor 8 can be moved further until the first sensor 8 hits the rail 25. This distance defines the pressing distance 12, since when the pressing distance 12 is traveled, the press ram 6 is pressed onto the workpiece. The predetermined pressing distance 12 corresponds to the height of the body 13.

[0027] For a description of the method according to the invention using the hand press according to the invention, Fig. 1 to Fig. 4. First, the workpiece is placed on the press table 3. Then, the lever 21 is actuated so that the sleeve 5 with the press ram 6 is moved towards the workpiece until the press ram 6 touches the workpiece. If the lever 21 is actuated further and the sleeve is driven further towards the workpiece, the press ram 6 moves towards the sleeve 5 and the spring element 16 is tensioned, whereby the distance 7 between the press ram 6 and the sleeve 5 becomes smaller. If a certain distance 26, predefined by the micrometer screw 14, between the holding plate 20 and the body 13 is undershot, the first sensor 8 generates the first signal and sends the first signal to the fixing device 10. This predefined distance 26 corresponds to the predefined distance 9 between the sleeve and the press table 3.

[0028] As soon as the fixing device 10 receives the first signal, the clamping jaws 15 are activated and clamp the press ram 6 so that the distance 7 between the press ram 6 and the sleeve 5 is now fixed (see description of Fig. 2).

[0029] Furthermore, the first signal is sent to the slider 24, whereupon the body 13 is pushed away so that the first sensor 8 is no longer prevented from moving further by the body 13 (see description of Fig. 3 and Fig. 4). If the lever 21 is moved further, the press ram 6 is pressed onto the workpiece. The pressing distance 12 corresponds to the height of the body 13 until the press ram 6 hits the rail 25 of the slide 24.

[0030] Once the pressing path 12 has been covered and the workpiece has been pressed in, the lever 21 is actuated in such a way that the sleeve 5 and thus the press ram 6 are moved in a direction opposite to the workpiece until the second sensor 17 generates the second signal (see description of Fig. 1). The second signal is sent to the locking device 10, whereupon the locking between the press ram 6 and the sleeve 5 is released. The second signal is also sent to the slide 24, whereupon the body 13 is pushed to its starting position. In this way, the hand press 1 is returned to its starting position, and the pressing process can begin again. List of reference symbols 1 hand press 2 base frame 3 press table 4 Drive unit 5 quill 6 press rams 7 Distance between the press ram and the quill 8 First sensor 9 Predetermined distance between the quill and the press table 10 Fixing device 11 track limiters 12 Pressing line 13 bodies 14 Micrometer screw 15 clamping jaws 16 spring element 17 Second sensor 18 tripod-shaped part 19 Press head 20 retaining plate 21 levers 22 clamping cylinders 23 Drive 24 sliders 25 rail 26 Predetermined distance between the holding plate and the body 27 Predetermined distance between the fixing device and the press head 28 passage

Claims

[1] Hand press for pressing, joining or assembling workpieces, comprising a base frame (2), wherein the base frame (2) has a press table (3) for placing a workpiece, wherein the base frame (2) has a drive unit (4) for driving a quill (5) in the direction of the workpiece, wherein a press ram (6) is provided which is movable relative to the sleeve (5) in the direction of the workpiece, so that further movement of the sleeve (5), after the press ram (6) touches the workpiece, leads to a reduction of the distance (7) between the press ram (6) and the sleeve (5), wherein a first sensor (8) is provided which, when the sleeve (5) moves further in the direction of the workpiece after the press ram (6) has touched the workpiece, sends out a first signal when the distance (9) between the sleeve (5) and the press table (3) falls below a predetermined distance, wherein the sleeve (5) has a fixing device (10) which fixes the press ram (6) against the sleeve (5) at the first signal, wherein a path limiter (11) is provided which, upon the first signal, limits the pressing path of the sleeve (5) in the direction of the workpiece to a predetermined pressing path (12). [2] Hand press according to claim 1, wherein the path limiter (11) is designed as a body (13) which can be removed from the pressing path and whose height defines the predetermined pressing path (12). [3] Hand press according to claim 1 or 2, wherein the first sensor (8) has a micrometer screw (14) by means of which the predetermined distance (9) of the sleeve (5) to the press table (3) can be adjusted. [4] Hand press according to at least one of the preceding claims, wherein the drive unit (4) is a mechanical, an electrical, a pneumatic or a hydraulic drive unit (4). [5] Hand press according to at least one of the preceding claims, wherein the fixing device (10) mechanically, electrically, pneumatically or hydraulically fixes the press ram (6) against the sleeve (5). [6] Hand press according to at least one of the preceding claims, wherein the fixing device (10) has at least one clamping jaw (15) by means of which the press ram (6) is fixed against the sleeve (5). [7] Hand press according to at least one of the preceding claims, wherein a spring element (16) is arranged between the press ram (6) and the sleeve (5), which spring element maximizes the distance (7) between the press ram (6) and the sleeve (5) up to a stop before the press ram (6) touches the workpiece. [8] Hand press according to at least one of the preceding claims, wherein a second sensor (17) is provided which, when the sleeve (5) is driven in the opposite direction of the workpiece while the predetermined distance (9) between the sleeve (5) and the press table (3) is exceeded, emits a second signal, wherein in the case of the second signal the fixing device (10) releases the fixing between the sleeve (5) and the press ram (6), and wherein in the case of the second signal the path limiter (11) removes the limitation of the pressing path to the predetermined pressing path (12) of the sleeve (5) in the direction of the workpiece. [9] Method for pressing a workpiece by means of a hand press comprising a base frame (2) with a press table (3) on which a workpiece is placed, and with a drive unit (4) for driving a sleeve (5) in the direction of the workpiece, wherein a press ram (6) is provided which is movable relative to the sleeve (5) in the direction of the workpiece, comprehensively the procedural steps: Driving the quill (5) towards the workpiece until the press ram (6) touches the workpiece, Moving the sleeve (5) further in the direction of the workpiece so that the press ram (6) reduces its distance (7) to the sleeve (5), Emitting a first signal when a predetermined distance (9) between the sleeve (5) and the press table (3) is undershot, Fixing the press ram (6) relative to the quill (5) when sending the first signal, Limiting the pressing distance of the sleeve (5) from the predetermined distance (9) at which the first signal is transmitted to a predetermined pressing distance (12), Continue moving the sleeve (5) in the direction of the workpiece until the predetermined pressing distance (12) has been covered and the workpiece is pressed in. [10] Method according to claim 9, wherein when driving the sleeve (5) in the opposite direction of the workpiece, when the predetermined distance (9) between the sleeve (5) and the press table (3) is exceeded, a second signal is emitted, wherein when the second signal is emitted, the fixation between the press ram (6) and the press table (3) is released and the limitation of the pressing path of the sleeve (5) in the direction of the workpiece to a predetermined pressing path (12) is lifted.

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