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(11) | EP 1 854 566 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Compound machine |
| (57) An apparatus or machine (1) for carrying out operations on a mechanical workpiece
especially operations of the squeezing type e.g. machines for pressing, riveting,
clinching, cutting, etc. The machine (1) could be of stationary or hand-held type.
The power source could be of any type, hydraulic, pneumatic, electric, of manual type
etc. The apparatus or machine has a combined clinching and nipping function. |
Technical field
[0001] This invention relates to apparatuses or machines for carrying out operations on a mechanical workpiece especially operations of the squeezing type e.g. machines for pressing, riveting, clinching, cutting, etc. The machines could be of stationary or hand-held type. The power source could be of any type, hydraulic, pneumatic, electric, of manual type etc.
Background art
[0002] A machine according to the above typically makes one or several "strokes" (tool elements are approaching each other from opposite sides of the workpiece) towards the workpiece in order to achieve the expected effect. The opening between the active machine elements, for introducing the workpieces can be decreased in a first part of the stroke, the approach stroke, before the second part of the stroke typically with a higher force (power stroke) takes place. At the end of the power stroke very high forces are typically applied.
[0003] An apparatus or machine of this type could be exemplified by an apparatus for joining sheet formed members together by means of a technique usually called clinching, thereby producing leakproof or non-leakproof joints between the sheet formed members.
[0004] A joint of this type could be made by means of drawing said sheet formed members into a cup-shaped or protruding portion having a cylindrical or slightly conical side wall and a bottom wall and subsequently compressing said bottom wall creating a lateral extrusion of the same thereby forming a laterally enlarged shape which mechanically interlocks the sheet formed members.
[0005] Typically the machines used for clinching provide very high forces especially at the end of the joining procedure during the lateral extrusion of the material when the workpiece is squeezed between the tools in the form of a punch and a co-operating anvil. The counter forces are taken up by a C-frame which could have considerable dimensions due to the fact that the pressure between the two co-operating tools could be in the range of several tons.
[0006] On one hand, in order to make the machine safe, fast and stable it is an advantage to make the gap for introducing the workpieces between the co-operating tools, a punch and a die, narrow. On the other hand this is of course limiting the form and dimensions of the workpiece which could be operated on by the tool.
[0007] There has already been proposed solutions to this problem providing a C-frame comprising two parts arranged pivoting relative to each other. When entering the workpiece the C-frame is first opened in order to enlarge the gap between the tool parts. In this way it will be possible to use work-pieces with different geometries and larger dimensions. The C-frame is then closed which means that the active tool parts are brought closer to each other in an approach stroke which only needs a low force but should be relatively fast. The work stroke is then following which is carried out with much higher force.
Brief description of the invention
[0008] One object of the present invention is to provide a safety arrangement for an apparatus having an articulated C-frame for carrying out a squeezing type of operation on a mechanical workpiece.
[0009] This is achieved by giving the possibility to prolong the approach stroke, i.e. the first part of the stroke carried out with relatively low force compared to known procedures until contact between the tools and the workpiece. Thus, the tools can be brought to nip or squeeze the workpiece with a lower force at the end of the approach stroke which means that it will be absolutely impossible for the operator to enter e.g. a finger by mistake between the tools and the workpiece when the machine is ready to carry out the power stroke.
[0010] At the same time the contact between the tools and the workpiece in the nip with relatively low force means that it will possible to adjust the position of the workpiece held in said nip before the application of the power stroke. If however the workpiece is in position it will be possible to proceed directly to the power stroke.
[0011] A further object of the invention is to provide new and improved means for setting up the machine for the power stroke. The inventive solution proposes a movement of the activation piston-cylinder combination into position for the last part of the approach stroke and the power stroke in a plane perpendicular to the plane defined by the trajectory of the tool parts.
[0012] The above and further objects are realised by means of the present invention which is characterised according to the appended claims.
Brief description of the figures
[0013] Other objects, uses and advantages of this invention will be apparent from the reading of this description which proceeds with reference to the accompanying drawings forming part thereof and wherein:
figure 1
Figure 1 shows in a perspective view a first embodiment of the invention in the form
of a handheld machine.
figure 2
Figure 2 shows in a perspective view the embodiment according to figure 1 in a further
phase of its operation.
figure 3
Figure 3 shows in a further view the embodiment according to figure 1 and 2.
figures 4-6
Figures 4-6 illustrate in perspective views the transition movement between the position
in figure 1 and the position in figures 2 and 3.
figures 7-8
Figures 7-8 illustrate in perspective views further details of the embodiment according
to figures 1-6.
figure 9
Figure 9 shows in a perspective view a second embodiment of the invention in the form
of a handheld machine.
figure 10
Figure 10 shows in a perspective view and partly in section the embodiment according
to figure 9 in a further phase of its operation.
figure 11
Figure 11 shows in a perspective view and partly in section details of the second
embodiment of the invention.
figure 12
Figure 12 shows a proposed design of the main handle for the first or the second embodiment
of the invention.
figure 13
Figure 13 shows in section a design of the actuation mechanism.
figure 14
Figure 14 shows an example of a pneumatic logic circuit for controlling the operation
of the machine.
Detailed description of the invention
[0014] The invention will in the following be described with reference to an implementation on a hand-held machine generally designated 1, for the squeezing type of operation on a mechanical workpiece (not shown). As mentioned the inventive idea could also be implemented on stationary machines. Additionally the shown example refers to a machine operated by means of hydraulic pressure generated by means of a so called booster or pneumatic-hydraulic amplifier of a common type. This booster is here shown integrated with the machine but could as an alternative be connected to the machine by means of a flexible hydraulic tube as known in the prior art. The same tube could also for the purpose of transferring pneumatic control signals be provided with appropriate channels.
[0016] Figure 1 thus shows in a perspective view a first embodiment of the invention in the form of a handheld machine.
[0017] The C-frame in this example is articulated and comprises two parts or jaws 2 and 3 arranged pivoting in relation to each other around the pivoting point 4. A resilient means schematically illustrated as a spring 13 urges the jaws to separate. Suitable toolheads (only shown schematically) are fixed on the free end-portions 5 and 6 of the jaws 2 and 3, respectively. The workpiece (not shown) is to be entered between these end-portions 5 and 6.
[0018] The machine as here illustrated is designed for a right handed operator. The main handle 7 to be gripped by the right hand connects in this example the actual machine with the integrated booster 8. Machines of this type are usually supported by means of a cable from a rail, the ceiling or equivalent in the workshop. For fixing this cable to the machine a freely rotating support ring 9 of known type is provided at the front portion of the main handle.
[0019] An auxiliary handle 10 to be gripped by the left hand is arranged fixed to the lower jaw 3 of the machine. This handle is used as the main means for orienting the machine in relation to the workpiece. As will be described more in detail below the handle 7 with the booster 8 could be rotated around an axis parallel with a plane defined by the trajectory of the movable jaw 2. The handle 10 is preferably arranged perpendicularly to said plane.
[0020] Fixed to the front endportion of the handle 10 and rotating with the same is arranged a power unit 11 including a cylinder-piston assembly 12, cf. for instance figure 3. At the rear end of the booster two units 14, 15 forming part of the pneumatic control circuit are schematically shown. These units will be described more in detail below.
[0021] Figure 2 shows in a perspective view the embodiment according to figure 1 in a further phase of its operation. By means of turning the handle 7 in clockwise rotation a cam 18, cf. for instance figure 4, will lift the rear end of the pivoting jaw 2 against the force from the spring which will close the c-frame from fully open (about 40mm) to defining an opening of about 6mm. In this position the operator has the choice either to prolong the approach stroke hydraulically at low pressure into nipping contact between the tools and the workpiece or directly activate the power stroke.
[0022] Figure 3 shows in a further view the embodiment according to figure 1 and 2. On the lower side of the handle 7 an actuator 19 for the power stroke, i.e. the clinching operation is arranged. On the upper side a second actuator 20 for the nipping is included. The cylinder-piston assembly 12 integrated in the power unit 11 is also seen in position for either a nipping operation or a clinching operation.
[0023] Figures 4-6 illustrate in perspective views the transition movement between the position in figure 1 and the position in figures 2 and 3. In figure 4 a cam 18 forming part of the power unit 11 is shown. This cam is co-operating with the rear portion of the pivoting jaw 2 lifting the same which causes the tools to approach during the approach stroke, cf. figure 5. Figure 6 shows the machine in the same position as figure 3.
[0024] Figures 7-8 illustrate in perspective views further details of the embodiment according to figures 1-6. Especially figure 8 shows on the lower side of the jaw 3 an L-formed unit 21 which at the same time is a mechanical stop for the rotating movement of the power unit 11 and thus the handle 7 and constituting a safety arrangement for the machine. When in the position shown in figure 8 the leg extending to the left in the figure is blocking an air outlet on the power unit 11 which will be described more in detail below.
[0025] Figure 9 shows in a perspective view a second embodiment of the invention in the form of a handheld machine. In this embodiment the rotating movement of the main handle 7 has been replaced by a rotating movement by the auxiliary handle 10'. The main handle is here fixed to the lower jaw 3. The function of the actuators 19 and 20 are the same as described. On the side of the interface between the main handle and the power unit 11 is arranged a valve 22 operated by an L-formed unit 21' fixed on the power unit 11. The valve and the L-formed unit together form a security arrangement. If one or the other of the actuators 19, 20 should be operated by mistake before the power unit 11 is in position the control air will just blow out through the valve 22 against atmospheric pressure and nothing else will happen.
[0026] Figure 10 shows in a perspective view and partly in section the embodiment according to figure 9 in a further phase of its operation. In this position the valve 22 is activated which means that if now either actuator is operated a nipping operation or a clinching operation will be started. At the end portion of the main handle openings of four internal channels of the handle are shown. The oval opening 24 as a matter of fact constitutes two openings which will be shown below. The opening 23 is the opening of a channel for pneumatic control signals and the opening 25 is the opening of a channel for high or low pressure hydraulic liquid to the power unit 11 activating the nipping or clinching operation.
[0027] Figure 11 shows in a perspective view and partly in section details of the second embodiment of the invention. The channel for the hydraulic liquid 25 has been marked in black. The pneumatic valve 20 for the nipping operation is shown on the upper side of the handle and the actuator 19, 30 for the nipping operation is shown on the lower side.
[0028] Figure 12 shows a proposed design of the main handle for the first or the second embodiment of the invention. The channel 28 is always pressurised with pneumatic pressure. This channel arrives at the valve 22 which is closed when the machine is not in the position for nipping or clinching. This means that nothing will happen if the actuators are operated. Assuming that the machine is now in the position as illustrated in e.g. figure 10. This means that the valve 22 opens and the pressure will arrive in the channel 29. If the actuator 20 for nipping is now operated the return channel 27 will be pressurised giving a signal to the logic that hydraulic liquid with the lower pressure has to be delivered to the power unit 11. If on the other hand the actuator 19 for the clinching operation is activated then the piston 26 will instead open for the pressure to the return channel 30 back to the logic. The result will be delivery of high pressure hydraulic liquid to the power unit 11.
[0029] Figure 13 shows in section a design of the actuation mechanism for delivering the return control signals to the logic for actuators.
[0030] Figure 14 shows an example of a pneumatic logic circuit for controlling the operation of the machine. The ports 100 are constantly pressurised. When a clinching operation is ordered pressure will arrive at 30. This will open the valve 113 which will feed high pressure from the inlet 1 on the regulator 134 to the inlet 1 on the valve 113 and further to the gate 133. High pressure will thus operate the booster and deliver high pressure hydraulic pressure to the power unit 11.
[0031] When a nipping operation has been ordered the pressure signal will instead arrive at 27. This will open the valve 123 the machine is not in the position for nipping or clinching. This means that nothing will happen if the actuators are operated. Assuming that the machine is now in the position as illustrated in e.g. figure 10. This means that the valve 22 opens and the pressure will arrive in the channel 29. If the actuator 20 for nipping is now operated the return channel 27 will be pressurised giving a signal to the logic that hydraulic liquid with the lower pressure has to be delivered to the power unit 11. If on the other hand the actuator 19 for the clinching operation is activated then the piston 26 will instead open for the pressure to the return channel 30 back to the logic. The result will be delivery of high pressure hydraulic liquid to the power unit 11.
[0032] Figure 13 shows in section a design of the actuation mechanism for delivering the return control signals to the logic for actuators.
[0033] Figure 14 shows an example of a pneumatic logic circuit for controlling the operation of the machine. The ports 100 are constantly pressurised. When a clinching operation is ordered pressure will arrive at 30. This will open the valve 113 which will feed high pressure from the inlet 1 on the regulator 134 to the inlet 1 on the valve 113 and further to the gate 133. High pressure will thus operate the booster and deliver high pressure hydraulic pressure to the power unit 11.
1. apparatus or machine for carrying out operations on a mechanical workpiece especially
operations of the squeezing type e.g. machines for pressing, riveting, clinching,
cutting, etc. The machines could be of stationary or hand-held type. The power source
could be of any type, hydraulic, pneumatic, electric, of manual type etc.characterised in that it has a combined clinching and nipping function