JP4148874B2 - Method and apparatus for determining the presence or absence of galling in a press-fitting process - Google Patents

Description

  The present invention relates to a method and apparatus for determining the presence or absence of galling in a press-fitting process in an automatic assembly line or the like.

  In general, when a workpiece member is press-fitted, a cylinder is driven to move a plunger (rod) in a state where the workpiece member is placed at a press-fitting position of a member to be pressed. The press-fit member has a press-cut end that is a contact surface of the work member, and the plunger has a press-fit determination section from the press-fit start position to the press-fit end position until the lower end surface of the work member contacts the press cut end. Moving.

  Conventionally, in order to determine whether or not the press-fitting process has been normally performed, the thrust of the cylinder, that is, the press input of the work member by the plunger is detected during the press-fitting process. In order to detect press input, a gate is provided at an arbitrary position (point) during the press-fitting process. At each gate position, the pressure input is measured, and it is determined whether the measured pressure input is within a predetermined range.

  In the press-fitting process, galling may occur between the work member and the press-fitted member. The galling may occur when the coaxiality or concentricity between the work member and the press-fit member is impaired, or when foreign matter is mixed between the work member and the press-fit member. When galling occurs, even if the pressure input temporarily rises and it appears that the press-fitting is performed well, a sufficient press-fitting may not be obtained, resulting in a defective exposure.

  Conventionally, such a galling has not been detected.

In addition, as described above, in the case where the gate is provided at an arbitrary position during the press-fitting process, if galling is detected, the gate position is determined according to the position of the galling to determine whether the press-fitting is good or bad. It was difficult or impossible to set such a position in practice.
JP 2002-283149 A

  The present invention has been made in view of the above problems, and an object of the present invention is to determine the presence or absence of galling in the press-fitting process and to accurately determine the quality of press-fitting.

The present invention is a method for determining the presence or absence of galling in a step of press-fitting a work member into a press-fit member by a linearly driven rod, and acquiring thrust information and position information of the rod during the press-fitting step, When the peak of the thrust of the rod is detected based on the thrust information , the peak value is set to FFP, and the lower set value (FFP-L) set to a value lower than the peak value FFP by the lower limit range L respect, it is determined that the thrust at a position after the position of the peak when it becomes lower than the lower set value (FFP-L), galling during the press-fitting step has Tsu cry.

  Further, when the peak of the thrust of the rod is not detected based on the thrust information, it is determined that there is a galling during the press-fitting process and it is determined that press-fitting is not possible.

  According to the present invention, it is possible to determine the presence or absence of galling in the press-fitting process, thereby making it possible to accurately determine the quality of press-fitting.

  FIG. 1 is a diagram showing a configuration of a press-fitting system PF using a determination device 1 according to the present invention, and FIG. 2 is a diagram for explaining an operation for detecting galling in the determination device 1. In FIG. 2, the vertical axis represents the thrust TH of the cylinder CY, that is, the pressure input by the press-fit jig PR, and the horizontal axis represents the position LL of the press-fit jig PR.

  As shown in FIG. 1, the press-fitting system PF includes a press-fitting device, a determination device 1, a sequencer 18, and the like. The press-fitting device includes a cylinder CY, a load cell 11, a position sensor 12, and the like. The determination apparatus 1 includes amplifiers 13 and 14, an arithmetic processing unit 15, a setting unit 16, a memory 17, and the like. The determination apparatus 1 can be configured using a CPU, a ROM and a RAM in which appropriate programs are stored, other memories, peripheral elements, an appropriate hardware circuit, and the like.

  The cylinder CY is fixed to an appropriate frame FM via a support fitting FA, and a press-fitting jig PR is attached to the tip of the piston rod PD. A press-fitting member BZ is disposed immediately below the press-fitting jig PR.

  In a state where the work member WK is placed at the press-fit position AP of the press-fit member BZ, the work member WK is press-fit into the press-fit member BZ by driving the cylinder CY and moving the press-fit jig PR downward. The press-fit member BZ has a pressing end KT which is a contact surface of the work member WK, and the press-fitting jig PR is press-fitted from the press-fitting start position LL1 until the lower end surface of the work member WK comes into contact with the press-cut end KT. Move the press-fitting section to the end position LLE.

  The load cell 11 detects the thrust TH of the cylinder CY, that is, the pressure input of the work member WK by the press-fitting jig PR. The amplifier 14 amplifies the output signal of the load cell 11 and outputs a thrust signal S1.

  The position sensor 12 detects the position LS of the press-fitting jig PR and the work member WK by detecting the position of the piston rod PD in the cylinder CY. The amplifier 13 outputs a position signal S2 based on the output from the position sensor 12. The amplifiers 13 and 14 may include appropriate converters for signal conversion.

  The arithmetic processing unit 15 includes a galling detection unit 15 a, a determination calculation unit 15 b, and a range setting unit 15 c, performs the determination of the presence or absence of galling, the determination of the quality of press-fitting, and sends a control signal CS to the sequencer 18. The processing contents of the arithmetic processing unit 15 will be described later.

  The setting unit 16 is for setting various values such as a data acquisition start position LL2, an upper limit range U, a lower limit range L, and a galling determination distance LH described below.

  The data acquisition start position LL2 is the position of the work member WK when the memory 17 starts storing the thrust signal S1 and the position signal S2. The data acquisition start position LL2 is appropriately set according to the shape and the like of the work member WK and the press-fit member BZ. The press-fit end position LLE is a position where the press-fit is finished. For example, the stroke end of the press-fitting jig PR, the time when the pressure input becomes substantially equal to the thrust of the PR cylinder CY, and the like. Data from the data acquisition start position LL2 to the press-fitting end position LLE (data acquisition section RM) is stored in the memory 17.

  That is, the memory 17 stores the thrust signal S1 and the position signal S2 in the data acquisition section RM as press-fitting data (thrust information) and position data (position information). These are stored in association with each other. Further, the memory 17 stores a value (set value) set by the setting unit 16.

  The sequencer 18 performs overall control of the press-fitting system PF based on the control signal CS sent from the arithmetic processing unit 15.

  Next, the operation and processing of the arithmetic processing unit 15 will be described.

  First, the determination of the presence or absence of galling by the galling detection unit 15a will be described.

  As shown in FIG. 2, the thrust signal S1 and the position signal S2 are acquired and stored in the memory 17 between the data acquisition start position LL2 and the press-fitting end position LLE. A peak PK is detected based on the thrust signal S1. In detecting the peak PK, for example, the rate of change with respect to the position of the thrust signal S1 is checked, and the time when the rate of change changes from positive to negative is detected as the peak PK. When the rate of change of the thrust signal S1 does not change from positive to negative, the peak PK is not detected.

  The value of the thrust signal S1 when the peak PK is detected is the peak value FFP, and the position at that time is the peak position LP. The position behind the detected peak position LP by the galling determination distance LH (the right position in FIG. 2) is the galling determination position LLH.

  In addition, a value (FFP + U) that is higher by the upper limit range U than the detected peak value FFP is the upper set value FFU, and a value that is lower by the lower limit range L (FFP-L) is the lower set value FFL.

  When the peak value FFP is detected, the value of the thrust signal S1 at the galling determination position LLH is checked, and when it is equal to or lower than the lower set value FFL, it is determined that there is no galling during the press-fitting process.

  That is, when the peak value FFP is detected and the value of the thrust signal S1 at the galling determination position LLH is equal to or lower than the lower set value FFL, it is determined that there is no galling.

  This is because actual press-fitting starts from the time when the workpiece member WK is pressed against the press-fitted member BZ by being pressed by the press-fitting jig PR, but the press input is increased after the press-fitting is started, and the press input is performed at a certain point. After reaching the peak, the pressure input drops to a certain value. However, if there is a galling, the pressure input does not decrease after reaching the peak, or even if the pressure input decreases. This is because foreign matter is caught. Therefore, the presence or absence of galling is determined as described above.

  Incidentally, in FIG. 2, when the curve B1 indicated by the chain line is obtained as the pressure input, the value at the galling determination position LLH is equal to or higher than the lower set value FFL, so the peak value FFP is detected even though it is detected. It is determined that there is a galling. If the curve B2 is obtained, the peak value FFP is not detected, so it is determined that there is a galling. When the curve B3 is obtained, since the peak value FFP is not detected, it is also determined that there is galling.

  Depending on the shape of the workpiece member WK, the peak value FFP may be detected at a plurality of locations. In such a case, the above-described check may be performed on each peak value FFP to determine the presence or absence of galling. In that case, the set values of the upper limit range U, the lower limit range L, and the galling determination distance LH may be made different for each peak value FFP.

  Further, after detecting the peak value FFP, the rate of decrease (differential value, slope) of the thrust signal S1 is checked, and if the absolute value of the rate of decrease does not become larger than a predetermined value, it is determined that there is a galling. May be.

  It should be noted that methods other than those described above can be adopted as a method for detecting the peak value FFP. In detecting the peak value FFP, various methods can be employed for using the data of the thrust signal S1. For example, an average value for a plurality of data is used, or calculation is performed by excluding specific data.

  Next, the determination of the quality of press-fitting by the determination calculation unit 15b will be described.

  If it is determined that there is a galling, it is determined that press-fitting is not possible. When it is determined that there is no galling, and when the value of the thrust signal S1 thereafter exceeds the upper set value FFU, it is determined that the press-fitting is good. That is, in this case, it is determined that the workpiece member WK has been normally press-fitted with a predetermined pressure input.

  Therefore, even if it is determined that there is no galling, if the subsequent thrust signal S1 does not exceed the upper set value FFU, it is determined that press-fitting is not possible. This is because the pressure input should increase due to the lower end surface of the work member WK coming into contact with the cut end KT, but if it does not exceed the upper set value FFU, it does not come into contact with the cut end KT. Because it will be. Therefore, such a check is unnecessary in the case of the press-fit member BZ that does not have the cut-off end KT.

  Various other methods can be employed in determining whether the press-fitting is good or bad. For example, the methods described in JP-A-2002-283149 and JP-A-2000-158244 can be employed.

  The sequencer 18 outputs an instruction AS necessary for the next press-fitting to the cylinder CY or the like in real time based on the control signal CS.

  Thus, according to the determination apparatus 1 of the present embodiment, it is possible to accurately determine the presence or absence of galling in the press-fitting process, and to accurately determine whether or not the press-fitting is good.

  In the above-described embodiment, the data acquisition section RM is set from the data acquisition start position LL2 to the press-fit end position LLE. However, the data acquisition start position may be widened as, for example, the press-fit start position. The shape, size, material, and the like of the press-fitting jig PR can be various. The press-fitting jig PR is attached to the tip of the piston rod PD, but may be integrated with the piston rod PD. The load cell 11 may be attached to the tip of the piston rod PD.

  In the above-described embodiment, the configuration, structure, size, shape, material, number, and the like of the entire determination device 1 and the press-fitting system PF or each part can be variously changed in accordance with the gist of the present invention.

  It can be used to determine whether or not parts are press-fitted, bearing press-fitting, pulley press-fitting, and other various member press-fitting in an automobile engine cylinder head assembly line.

It is a figure which shows the structure of the press injection system using the determination apparatus which concerns on this invention. It is a figure for demonstrating the operation | movement of the galling in a determination apparatus.

Explanation of symbols

1 judgment device 11 load cell (thrust detection means)
12 Position sensor (position detection means)
15a Scratch detection part (determination means)
15b Determination calculation unit (means for determination)
16 Setting part (means for giving)
17 Memory (memory means)
PR Press fitting jig BZ Press fit member WK Work member RM Data acquisition section (predetermined stroke range)
S1 Thrust signal (thrust information)
S2 Position signal (position information)
PK Peak FFP Peak value FFU Upper set value FFL Lower set value LL2 Data acquisition start position LLH Judgment position (position after the peak position)

Claims (3)

A method for determining the presence or absence of galling in a step of press-fitting a workpiece member into a press-fit member by a linearly driven rod,
Obtaining thrust information and position information of the rod during the press-fitting process;
When the peak of the thrust of the rod is detected based on the thrust information, the peak value is set to FFP, and the lower set value (FFP-L) set to a value lower than the peak value FFP by the lower limit range L On the other hand, when the thrust becomes a value lower than the lower set value (FFP-L) at a position after the peak position, it is determined that there is no galling during the press-fitting process.
A method for determining the presence or absence of galling in press-fitting, characterized in that. An apparatus for determining the presence or absence of galling in the process of press-fitting a work member into a press-fit member by a linearly driven rod,
Thrust detecting means for obtaining thrust information in a predetermined stroke range of the rod;
Position detecting means for obtaining position information in a predetermined stroke range of the rod;
Storage means for storing the thrust information and the position information;
Means for detecting a thrust peak of the rod based on the thrust information;
Means for giving a lower set value (FFP-L) which is a value lower than the lower limit range L to the peak value FFP of the detected peak;
When the thrust at a position after the position of the peak was lower than the lower set value (FFP-L), means for determining that there was no galling during the press-fitting step,
An apparatus for determining the presence or absence of galling in press-fitting, comprising: An apparatus for determining whether or not the press-fitting is good in the step of press-fitting the work member into the press-fitted member by a linearly driven rod,
Thrust detecting means for obtaining thrust information in a predetermined stroke range of the rod;
Position detecting means for obtaining position information in a predetermined stroke range of the rod;
Storage means for storing the thrust information and the position information;
Means for detecting a thrust peak of the rod based on the thrust information;
Means for giving an upper set value (FFP + U) that is an upper value by an upper limit range U and a lower set value (FFP-L) that is a lower value by a lower limit range L relative to the peak value FFP of the detected peak;
Means for determining that there was no galling during the press-fitting process when the thrust is lower than the lower set value (FFP-L) at a position after the peak position;
Means for determining that the press-fitting has been normally performed when the thrust becomes higher than the upper set value (FFP + U) after determining that there is no galling;
A press-fitting quality determination device characterized by comprising:

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