CN1890068A - Control of cutting equipment and cutting equipment - Google Patents

Abstract

The invention relates to a cutting device, for a bonding machine, with a cutting blade for separating a bonding wire, whereby the cutting blade is directly or indirectly mounted on a main displacement device of a bonding machine, such as to be displaced in a vertical projection direction. On placing the cutting blade on a wire for at least partial cutting, by displacement of the main displacement device the cutting blade may be applied with a cutting force for application to the wire, by means of a spring element. The invention further relates to a method for control of the cutting process.

Description

Control of cutting equipment and cutting equipment

The invention relates to a cutting device for a bonding machine (Bondmaschine), comprising a cutting knife for cutting the bonding wire (Bonddraht), wherein the cutting knife is fixed directly or indirectly to the main movement of the bonding machine, movable along a vertical feed direction on the device. Furthermore, the invention relates to a method of controlling the cutting movement of a cutter when at least partially cutting a bond wire in a bonding machine.

Cutting devices in bonding machines are known, which are used to at least partially sever the bonding wire. It is known in this respect that the cutting knife is provided with a separate drive in order to be able to drive the cutting knife independently of a main movement device or to drive the cutting knife directly by means of a main movement device.

Both of these methods do not provide accurate information about the actual forces acting on the joint wire, so the cutting forces can only be controlled or adjusted less satisfactorily.

The object of the present invention is to provide a device and a method with which reliable control/regulation of the bonding force (Bondkraft) can be achieved and which preferably also provide information on the degree of wear of the cutting knife, that is to say on the current sharpness of the knife information.

The measure taken for this purpose is that, when the cutting knife rests on a joint wire to be cut at least partially, the cutting knife can exert an action on the joint wire by means of an elastic element by means of the movement of said main movement device. cutting force.

Since the force is not exerted directly by the main movement device but by means of an elastic element such as a pressure spring, leaf spring or the like, the cutting force is generated essentially from a static force effect obtained by means of the elastic element. According to the movement distance of the cutter relative to the main movement device or a fixed zero position relative to the main movement device and the more or less compression or extension of the elastic element associated therewith, the said force.

In order to achieve this, the elastic element is preferably arranged between the knife support and a component of the main movement device, wherein the knife support is movable especially by means of a rotary hinge, a linear guide or a solid hinge Ground mounted on the main movement device.

According to an advantageous configuration, the movement distance of the cutting knife relative to the main movement device, in particular relative to a zero position, can be determined by means of a sensor. Likewise, the velocity of the tool relative to the joint line may be known or measurable.

Thus, with the device according to the invention it is possible to determine the cutting force as a function of the relative position of the cutting knife with respect to its zero position. For this purpose, it can be determined from the position of the cutting knife relative to a zero point position and the force characteristic line of an elastic element that can be tightened by the movement of the cutting knife and by means of which force is exerted by the cutting knife on the joint line. The force exerted by the knife on the joint wire.

In addition to determining the force by means of the position of the cutter, the velocity of the cutter can also be used for setting the force.

After comparing the determined actual force with a setpoint force or a setpoint force range, the actual force can be adjusted, for example by changing the position of the cutter relative to the zero position and/or the speed of the cutter. As a result, the deflection of the spring element is changed and, based on the force characteristic curve of this spring element, the applied force is also changed.

This force is also a function of the speed of motion of the cutter relative to the bond wire. This movement speed can be determined by means of the movement speed of the main movement device before the cutting knife rests on the joint line. After resting, the cutting knife cuts into the joint line due to the acting elastic force, at this time, the main movement device moves in the Z direction until it reaches a set cutting depth. In this case, the cutting force is continuously monitored during the cutting process. If the cutting force exceeds a maximum permissible value, the movement parameters of the main movement device must be adjusted, in particular the speed can be reduced for this purpose.

According to the invention, the cutting process and in particular the desired cutting force can be controlled and/or readjusted to a large extent very precisely.

By comparing the determined cutting force and cutting speed with predetermined maximum and minimum cutting forces or cutting speeds, the degree of cutter wear can be known. Especially when a predetermined maximum cutting force is exceeded and a predetermined minimum cutting speed is approached or undershot, it can thus be concluded that the cutting knife is no longer sufficiently sharp and has to be replaced due to wear.

Compared to the previously known methods, which only change the knives according to a certain number of cutting operations, the method according to the invention has the advantage, in addition to the control/adjustment force, that the knives can be changed as required.

The invention will be described in detail below with the aid of the embodiments shown in the drawings.

Figures 1 and 2 illustrate the method and apparatus according to the invention.

Figure 1 shows at least a part of the main kinematic means 1 of a combining machine. A transducer 2 (not shown in detail) with an ultrasonic tool 3 is fastened to this part.

A cutter support 5 is connected to the main moving device 1 via a rotary hinge 4, so that they can move relative to each other. Attached to the knife holder 5 is a knife 6 pointing vertically downward toward the bonding point, the lower tip of which is bent as shown in the figure.

When the main moving device moves downward along the Z direction, the cutting knife 6 rests on the joint line not shown in the figure. The initial force is mainly caused by the travel of the primary movement device 1 beyond the zero position. As a result, the spring 7 between the cutter holder 5 and the main movement device 1 is compressed, so that a force corresponding to this spring force acts on the joint wire via the cutter 6 and cuts the joint wire. Decisive for the force is the degree of compression of the spring, which is influenced by the speed of the main moving device and the sharpness of the knife.

The force or deflection can be measured by a position sensor 8 which determines the position of the tool 6 relative to the zero position. The current force can then be determined with the aid of the force characteristic curve, and influencing parameters, such as the cutting speed, can be recalculated for the next cutting process, for example, in the event of a deviation from the desired force.

If the speed of the main kinematics falls below a minimum speed and the force then exceeds a maximum force, this is especially a sign that the knife 6 is blunt and should therefore be replaced.

FIG. 2 shows a front sectional view of the device according to another design, in which a spring steel connection has been chosen instead of a swivel hinge connection in order to flexibly connect the tool holder and the main movement device to one another.

Claims (7)

1. cutting equipment that is used in conjunction with machine, it comprises a cutting knife that is used to cut off closing line, wherein, this cutting knife can directly or indirectly be fixed on the main motion device in conjunction with machine along the vertical feed direction with moving, it is characterized by: when cutting knife rests on the closing line that will partly cut at least, by the motion of described main motion device, described cutting knife can apply a cutting force that acts on this closing line by a flexible member.

2. according to the described cutting equipment of claim 1, it is characterized by, described flexible member is arranged between the member of a cutter supporter and described main motion device, wherein, this cutter supporter especially is contained on the described main motion device movingly by a rotary gemel, a straight line guiding device or solid hinge.

3. according to claim 1 or 2 described cutting equipments, it is characterized by,, especially can determine by a sensor with respect to the described move distance of a dead-center position with respect to described main motion device.

4. according to the described cutting equipment of above-mentioned each claim, it is characterized by, can determine described cutting force with respect to the relative position of its dead-center position according to described cutting knife.

5. a cutting movement that is used for controlling in conjunction with the cutting knife of machine comes to the method for small part cutting closing line, especially can be by according to the described cutting equipment of above-mentioned each claim in this method, it is characterized by: the power characteristic curve of the flexible member that can be tauted by the motion of described cutting knife with respect to the position of a dead-center position and according to described cutting knife, determine to be applied to power on the closing line, power is applied on the described closing line via cutting knife by this flexible member by cutting knife.

6. according to the described method of above-mentioned each claim, it is characterized by, by determined actual forces and a nominal force or a nominal force interval are compared, adjust the actual forces that is used for next cutting process by this way by the speed that redefines described main motion device, that is, make it to be in the power interval that is allowed.

7. according to the described method of above-mentioned each claim, it is characterized by, according to determined cutting force, when especially when a predetermined minimum cut speed, surpassing a predetermined maximum cutting force, know the degree of wear of described cutting knife, change a cutter by described in conjunction with confidential asking especially in this case.

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