Remaining amount estimation device and remaining amount estimation method

Abstract

The residual quantity estimation device (30) of the present invention estimates the residual quantity (S) of the metal wire on the metal wire spool (18) wound on the metal wire electrode (16), and includes: an acquisition unit (50) that acquires the first rotational position (60) of the metal wire spool (18) and the second rotational position (62) of the wire feed roller (20) that feeds out the metal wire electrode (16); and a first estimation calculation unit (52) that estimates the residual quantity (S) of the metal wire using the ratio of the rotation amount of the metal wire spool (18) and the wire feed roller (20) at the beginning and end of a predetermined period (T) and the total rotation amount (φ) of the wire feed roller (20) during the predetermined period (T).

Description

Technical Field

[0001] The present invention relates to a residual quantity estimation device for estimating the residual quantity of a metal wire electrode wound on a metal wire spool of a wire EDM machine, and a residual quantity estimation method performed by the residual quantity estimation device. Prior Technology

[0002] A wire electrical discharge machining (EDM) machine performs electrical discharge machining using a wire electrode. The wire electrode is pre-wound onto a wire spool. The amount of wire electrode wound onto the wire spool is also referred to below as "wire residual weight".

[0003] The residual metal wire gradually decreases during electrical discharge machining (EDM). When the residual metal wire is depleted during EDM, the EDM process is interrupted. Japanese Utility Model Publication No. 02-039824 discloses a prior art method for preventing this interruption. This prior art relates to a method for calculating the residual metal wire. This prior art includes calculations using the density and roll diameter of the metal wire electrodes. Furthermore, the density is described as roll ratio in Japanese Utility Model Publication No. 02-039824. Summary of the Invention

[0004] The aforementioned prior art has at least the following drawbacks. To implement the prior art, the operator must measure both the density and the roll diameter. This measurement of both density and roll diameter is a burden on the operator.

[0005] The purpose of this invention is to solve the above-mentioned problems.

[0006] The first embodiment of the present invention is a residual quantity estimation device for estimating the residual quantity of metal wire on the metal wire reel of a wire EDM machine, which includes a wire reel, a wire feeding roller for feeding a metal wire electrode wound on the wire reel, a first rotational position detection sensor for detecting a first rotational position of the wire reel, and a second rotational position detection sensor for detecting a second rotational position of the wire feeding roller. The device further includes: an acquisition unit for obtaining the first rotational position and the second rotational position; and a first estimation calculation unit for estimating the residual quantity of metal wire at the end of the predetermined period based on the ratio of the rotational amount of the wire reel to the wire feeding roller at the beginning of a predetermined period (i.e., a first ratio), the ratio of the rotational amount of the wire reel to the wire feeding roller at the end of the predetermined period (i.e., a second ratio), and the total rotational amount of the wire feeding roller during the predetermined period.

[0007] The second aspect of the present invention is a method for estimating the residual amount of metal wire on the wire reel of a wire EDM machine, comprising a wire reel, a wire feeding roller for feeding a metal wire electrode wound on the wire reel, a first rotational position sensor for detecting a first rotational position of the wire reel, and a second rotational position sensor for detecting a second rotational position of the wire feeding roller. The method includes the following steps: obtaining the first rotational position and the second rotational position; and estimating the residual amount of metal wire at the end of the predetermined period based on the ratio of the rotational amount of the wire reel to the wire feeding roller at the beginning of a predetermined period (i.e., a first ratio), the ratio of the rotational amount of the wire reel to the wire feeding roller at the end of the predetermined period (i.e., a second ratio), and the total rotational amount of the wire feeding roller during the predetermined period.

[0008] Through the various forms of this invention, the amount of metal wire residue can be obtained while reducing the workload of operators.

[0009] The aforementioned objectives, features, and benefits should be readily understood from the following embodiments illustrated with reference to the accompanying drawings. Simple Explanation of the Diagram

[0010] Figure 1 is a diagram of the residual estimation system based on the implementation state.

[0011] Figure 2 is a schematic diagram of the residual estimation device shown in Figure 1.

[0012] Figure 3 is a flowchart illustrating the process of residual estimation method according to the implementation state.

[0013] Figure 4 is a diagram of the residual estimation device according to Modified Example 1.

[0014] Figure 5 is a schematic diagram of a metal wire reel with a metal wire electrode wound on it.

[0015] Figure 6 shows an example of the structure of a reference table stored in the storage section.

[0016] Figure 7 is a flowchart illustrating the residual estimation method according to Modified Example 1.

[0017] Figure 8 is a diagram of the residual estimation device according to Modified Example 2.

[0018] Figure 9 is a diagram of the residual estimation system based on Modified Example 3.

[0019] Figure 10 is a schematic diagram of a predetermined period. Implementation

[0020] [Implementation Status] Figure 1 is a configuration diagram of the residual quantity estimation system 10 according to the implementation sample. Furthermore, the diagram in Figure 1 not only includes the residual quantity estimation system 10, but also includes the wire feeding mechanism 14 of the wire EDM machine 12.

[0021] The wire feeding mechanism 14 includes a metal wire reel 18, a plurality of wire feeding rollers 20 and two motors 22.

[0022] The wire reel 18 is a rotatable reel. Point O in Figure 1 indicates the axis of rotation of the wire reel 18 (see also Figure 5). A wire electrode 16 is wound on the wire reel 18. The wire electrode 16 is the wire used for electrical discharge machining. The wire electrode 16 is pulled out from the wire reel 18.

[0023] The plurality of wire feeding rollers 20 are rotatable rollers. The plurality of wire feeding rollers 20 includes a first roller 201 and a second roller 202. The metal wire electrode 16 drawn from the metal wire spool 18 is sequentially mounted on the first roller 201 and the second roller 202.

[0024] The plurality of wire feeding rollers 20 further includes auxiliary rollers 203. The auxiliary rollers 203 change the direction of travel of the metal wire electrode 16. Furthermore, the auxiliary rollers 203 reduce the bending of the metal wire electrode 16. The number of auxiliary rollers 203 is not particularly limited. The location of the auxiliary rollers 203 is also not particularly limited.

[0025] The two motors 22 are, for example, servo motors. The two motors 22 include a first motor 221 and a second motor 222. The first motor 221 rotates the first roller 201. The second motor 222 rotates the second roller 202.

[0026] The two motors 22 are each controlled by a control device 24. The control device 24 is an electronic device (computer) used to control the wire electrical discharge machine 12. The control device 24 is, for example, a computerized numeric controller (CNC).

[0027] The wire feeding mechanism 14 further includes two wire guides 25. The two wire guides 25 are positioned between the first roller 201 and the second roller 202 (see Figure 1). The workpiece W is positioned between the two wire guides 25. By rotating the first roller 201 and the second roller 202, the wire electrode 16 is fed from the wire spool 18 to the workpiece W. The wire electrode 16 is then conveyed through the workpiece W to a recycling bin. The recycling bin is not shown in the figure.

[0028] The wire electrode 16 is fed from the wire spool 18 to the workpiece W while moving relative to the workpiece W. The relative movement of the wire electrode 16 is based on machining program 48. Machining program 48 specifies the path of relative movement of the wire electrode 16. Machining program 48 is input to the control device 24 (see Figure 2).

[0029] Furthermore, a voltage is applied to the metal wire electrode 16. This generates a discharge between the metal wire electrode 16 and the workpiece W. The voltage is applied to the metal wire electrode 16 based on processing conditions 46. Processing conditions 46 include one or more parameters. Processing conditions 46 are input to the control device 24 (see Figure 2).

[0030] The workpiece W is processed by the relative movement of the wire electrode 16 and the discharge between the wire electrode 16 and the workpiece W. However, if the remaining wire is exhausted during the processing of the workpiece W, the wire EDM machine 12 will stop during processing. In this case, the operator performs replenishment work on the wire electrode 16 (replacement of the wire reel 18) and re-laying of the wire electrode 16. However, such work will increase the operator's workload. Therefore, it is important for the operator to check the remaining wire before processing.

[0031] However, detecting residual metal wire is not easy for operators. For example, in implementing the aforementioned techniques, operators must measure both the density and the roll diameter. Measuring both density and roll diameter is a significant burden for operators. In particular, accurately measuring the density is quite difficult for operators.

[0032] Based on the above preliminary description, the residual quantity estimation system 10 will be described. The residual quantity estimation system 10 is a system for estimating the residual quantity S of the metal wire. The residual quantity estimation system 10 includes a first rotational position detection sensor 26, a second rotational position detection sensor 28, and a residual quantity estimation device 30 (see Figure 1).

[0033] The first rotational position detection sensor 26 is a sensor used to detect the rotational position of the wire spool 18. The first rotational position detection sensor 26 is appropriately installed in the wire EDM machine 12. The first rotational position detection sensor 26 outputs a signal corresponding to the rotational position of the wire spool 18. In the following description, the signal corresponding to the rotational position of the wire spool 18 is also referred to as the first detection signal 32. The first detection signal 32 is input to the residual weight estimation device 30.

[0034] The second rotational position detection sensor 28 is a sensor used to detect the rotational position of the first roller 201. The second rotational position detection sensor 28 is appropriately installed in the wire EDM machine 12. The second rotational position detection sensor 28 outputs a signal corresponding to the rotational position of the first roller 201. In the following description, the signal corresponding to the rotational position of the first roller 201 is also referred to as the second detection signal 34. The second detection signal 34 is input to the residual weight estimation device 30.

[0035] Furthermore, the second rotational position detection sensor 28 can also detect the rotational position of the shaft of the first motor 221.

[0036] Figure 2 is a structural diagram of the residual estimation device 30 in Figure 1.

[0037] The residual quantity estimation device 30 is an electronic device for estimating the residual quantity S of the metal wire. The residual quantity estimation device 30 also serves as the control device 24 of the wire EDM machine 12. The residual quantity estimation device 30 includes a display unit 36, an operation unit 38, a storage unit 40, and a calculation unit 42 (see Figure 2).

[0038] Display unit 36 ​​is a display device having a display screen 361. Information is appropriately displayed on the display screen 361. The material of display unit 36 ​​includes liquid crystal. However, the material of display unit 36 ​​is not limited to liquid crystal. For example, the material of display unit 36 ​​may also include OEL (Organic Electro-Luminescence).

[0039] The operation unit 38 is an input device for receiving information input from the operator. The operator can input information into the residual quantity estimation device 30 through the operation unit 38. The operation unit 38 may include, for example, a control panel, a mouse, a keyboard, and a touch panel. The touch panel is located on the display screen 361.

[0040] Storage unit 40 has memory. For example, storage unit 40 has RAM (Random Access Memory) and ROM (Read Only Memory).

[0041] The storage unit 40 stores a residual quantity estimation program 44. The residual quantity estimation program 44 is used by the residual quantity estimation device 30 to estimate the residual quantity S of the metal wire. Furthermore, the information stored in the storage unit 40 is not limited to the residual quantity estimation program 44. Various types of information can be appropriately stored in the storage unit 40 as needed. For example, in this embodiment, the residual quantity estimation device 30 also functions as a control device 24. In this case, processing conditions 46 and processing formula 48 can also be stored in the storage unit 40.

[0042] The computing unit 42 has a processor. For example, the computing unit 42 has a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). The computing unit 42 may appropriately refer to information stored in the storage unit 40.

[0043] The calculation unit 42 includes an acquisition unit 50, an estimation calculation unit (first estimation calculation unit) 52, a comparison unit 54, an alarm generation unit 56, and a display control unit 58 (see Figure 2). The acquisition unit 50, the estimation calculation unit 52, the comparison unit 54, the alarm generation unit 56, and the display control unit 58 are implemented by the calculation unit 42 executing the residual estimation program 44.

[0044] The acquisition unit 50 includes a first signal analysis unit 501 and a second signal analysis unit 502 (see Figure 2).

[0045] The first signal analysis unit 501 analyzes the first detection signal 32. Thereby, the first signal analysis unit 501 obtains the first rotation position 60. The first rotation position 60 represents the rotation position of the wire reel 18. The first rotation position 60 is stored in the storage unit 40. The first rotation position 60 is provided for reference by the estimation calculation unit 52.

[0046] The second signal analysis unit 502 analyzes the second detection signal 34. Thereby, the second signal analysis unit 502 obtains the second rotation position 62. The second rotation position 62 represents the rotation position of the first roller 201. The second rotation position 62 is stored in the storage unit 40. The second rotation position 62 is provided for reference by the estimation calculation unit 52.

[0047] The estimation calculation unit 52 includes a ratio calculation unit 521 and a residual calculation unit 522 (see Figure 2).

[0048] The ratio calculation unit 521 calculates the first ratio α. The first ratio α represents the ratio of the rotation amount of the first roller 201 to the rotation amount of the wire reel 18. The first ratio α is calculated based on the first rotation position 60 and the second rotation position 62. However, the first ratio α is the ratio at the beginning of a predetermined period T. The predetermined period T is the period during which the wire electrode 16 is fed from the wire reel 18. The range of the predetermined period T can be arbitrarily specified by the operator. However, the range of the predetermined period T can also be automatically set by the residual quantity estimation device 30.

[0049] The first ratio α is expressed by the following mathematical formula (1). The values ​​represented by each symbol in mathematical formula (1) are as follows. That is, "α: the first ratio". "θ 18: the amount of rotation of the wire reel 18 at the beginning of the given period T". "θ 20: the amount of rotation of the first drum 201 at the beginning of the given period T".

[0050] [Formula 1]

[0051] The first ratio α is provided for reference in the residual quantity calculation section 522.

[0052] Figure 10 is a schematic diagram of a given period T. Figure 10 illustrates a time flow containing a given period T.

[0053] The denominator (rotation amount θ 18) in mathematical formula (1) is not zero. Therefore, the "beginning" of a given period T includes the period (TWA, TWA', or TWA'') corresponding to the degree of change of the first rotation position 60. In this case, the rotation amount θ 18 represents the change of the first rotation position 60 in period TWA, period TWA', or period TWA''. Also, the rotation amount θ 20 represents the change of the second rotation position 62 in period TWA, period TWA', or period TWA''.

[0054] In Figure 10, the starting point of the period TWA coincides with the starting point of the predetermined period T. The ending point of the period TWA is a point in time after the starting point of the predetermined period T.

[0055] The starting point of period TWA' in Figure 10 is a point in time before the starting point of the predetermined period T. The ending point of period TWA' coincides with the starting point of the predetermined period T.

[0056] In Figure 10, the starting point of period TWA'' is a time point before the starting point of the given period T. The ending point of period TWA'' is a time point after the starting point of the given period T.

[0057] Furthermore, if the first rotational position 60 and the second rotational position 62 are obtained by the acquisition unit 50 during period TWA' or period TWA'', the metal wire delivery begins before the start of the predetermined period T.

[0058] Furthermore, the ratio calculation unit 521 calculates a second ratio β. The second ratio β represents the ratio of the rotation amount of the first roller 201 to the rotation amount of the wire reel 18. The second ratio β is calculated based on the first rotation position 60 and the second rotation position 62. However, the second ratio β is the ratio at the end of a predetermined period T.

[0059] The second ratio β is expressed by the following mathematical formula (2). The values ​​represented by each symbol in mathematical formula (2) are as follows. That is, "β: the second ratio". "θ' 18: the amount of rotation of the wire reel 18 at the end of the given period T", "θ' 20: the amount of rotation of the first drum 201 at the end of the given period T".

[0060] [Equation 2]

[0061] The denominator (rotation amount θ' 18) in mathematical formula (2) is not zero. Therefore, the "end" of a given period T includes the period (TWB, TWB', or TWB'') corresponding to the degree of change of the first rotation position 60 (see Figure 10). In this case, rotation amount θ' 18 represents the change in the first rotation position 60 in period TWB, period TWB', or period TWB''. Also, rotation amount θ' 20 represents the change in the second rotation position 62 in period TWB, period TWB', or period TWB''.

[0062] In Figure 10, the starting point of period TWB is a time point before the end of the predetermined period T. The end point of period TWB coincides with the end point of the predetermined period T.

[0063] In Figure 10, the starting point of period TWB' coincides with the ending point of the predetermined period T. The ending point of period TWB' is a time point after the ending point of the predetermined period T.

[0064] In Figure 10, the starting point of period TWB'' is a time point before the end of the given period T. The ending point of period TWB'' is a time point after the end of the given period T.

[0065] Furthermore, if the first rotational position 60 and the second rotational position 62 are obtained by the acquisition unit 50 during period TWB' or period TWB'', the metal wire delivery continues after the end of the predetermined period T.

[0066] Furthermore, when the wire feeding mechanism 14 feeds out the metal wire electrode 16, the following mathematical formula (3) holds. The values ​​represented by each symbol in mathematical formula (3) are as follows: That is, "Q: roller radius (half the roller diameter)" (see Figure 1). "θ 20: rotation amount of the first roller 201". "R: radius of the metal wire electrode 16 wound on the metal wire drum 18 (half the drum diameter)" (see Figure 1). "θ 18: rotation amount of the metal wire drum 18".

[0067] [Formula 3]

[0068] The roller radius Q is fixed. In this case, the rotation amount θ 20 of the metal wire electrode 16 used to deliver a fixed amount is also fixed. On the other hand, the roller radius R will become shorter as the residual metal wire S decreases. Therefore, the rotation amount θ 18 of the metal wire electrode 16 used to deliver a fixed amount gradually increases based on mathematical formula (3).

[0069] Based on the above, the following relationships hold true. That is, the rotation amount θ20 in mathematical expression (1) is equal to the rotation amount θ'20 in mathematical expression (2) (θ20=θ'20). Also, the rotation amount θ18 in mathematical expression (1) is larger than the rotation amount θ'18 in mathematical expression (2) (θ18<θ'18). Therefore, the second ratio β is less than the first ratio α.

[0070] The second ratio β is provided for reference in the residual amount calculation unit 522.

[0071] The residual quantity calculation unit 522 calculates the residual quantity S of the metal wire based on the following mathematical formula (4). The values ​​represented by each symbol in the mathematical formula (4) are as follows: That is, "S: residual quantity of metal wire". "α: first ratio". "β: second ratio". "Q: drum radius". "L: drum radius of the metal wire reel 18 (half of the drum diameter)" (refer to Figure 1 or Figure 5). "φ: total rotation of the first drum 201". "π: pi".

[0072] [Formula 4]

[0073] Furthermore, the roller radius Q and the roller radius L are pre-stored in the storage section 40. The total rotation amount φ is the total amount of rotation of the first roller 201 during a predetermined period T. Therefore, the total rotation amount φ is obtained based on the second rotation position 62.

[0074] The residual metal wire S represents an estimated value of the residual metal wire electrode 16 wound on the metal wire spool 18 at the end of a predetermined period T. The residual metal wire S is provided for reference by the comparison unit 54.

[0075] The comparison section 54 compares the residual metal wire S with the estimated metal wire S'. The estimated metal wire S' is an estimate of the residual metal wire S required for electrical discharge machining. The estimated metal wire S' is calculated, for example, based on machining formula 48. Furthermore, the estimated metal wire S' can be calculated not only based on machining formula 48 but also based on machining conditions 46.

[0076] Furthermore, the comparison unit 54 determines whether the residual metal wire quantity S is less than the estimated metal wire quantity S'. The determination is based on the comparison result. If the residual metal wire quantity S is less than the estimated metal wire quantity S', the comparison unit 54 calls the alarm generation unit 56.

[0077] Alarm generation unit 56 generates an alarm. The alarm is generated in response to the comparison result. The alarm is generated in the form of a message that can be displayed on display unit 36. This message, for example, indicates that the residual metal wire S is less than the estimated metal wire S'. The generated alarm is provided for reference by display control unit 58.

[0078] The display control unit 58 controls the display unit 36. The display control unit 58 displays the estimated residual metal wire quantity S on the display screen 361. This allows the operator to know the residual metal wire quantity S. Furthermore, the display control unit 58 also displays the message generated by the alarm generation unit 56 on the display screen 361. This allows the operator to know that the residual metal wire quantity S is less than the estimated metal wire quantity S'.

[0079] Furthermore, the information displayed on the display screen 361 by the display control unit 58 is not limited to the residual metal wire quantity S and other information. For example, the display control unit 58 can also display the comparison results performed by the comparison unit 54 on the display screen 361.

[0080] The residual quantity estimation device 30 can calculate the residual quantity S of the metal wire without using the density and roll diameter (roll radius R). Therefore, the operator does not need to measure the density and roll diameter (roll radius R). Thus, the residual quantity estimation device 30 reduces the operator's workload. The above is a description of the residual quantity estimation device 30.

[0081] Figure 3 is a flowchart illustrating the process of residual estimation method according to the implementation state.

[0082] The residual quantity estimation method is a method used to estimate the residual quantity S of the metal wire. The residual quantity estimation method is executed by the residual quantity estimation device 30. The residual quantity estimation method includes an acquisition step 82, an estimation calculation step 84, a comparison step 86, an alarm generation step 88, and a display step 90 (see Figure 3).

[0083] The residual estimation device 30 performs the acquisition step 82. The acquisition step 82 includes a start determination step 821, a first acquisition step 822, an end determination step 823, and a second acquisition step 824 (see Figure 3).

[0084] In the initial determination step 821, the acquisition unit 50 determines whether the predetermined period T has started. When the predetermined period T starts (initial determination step 821: yes), the acquisition unit 50 executes the first acquisition step 822.

[0085] In the first acquisition step 822, the acquisition unit 50 acquires the first rotational position 60 and the second rotational position 62. The first rotational position 60 acquired here represents the rotational position of the wire reel 18 at the beginning of the predetermined period T. The second rotational position 62 acquired here represents the rotational position of the first drum 201 at the end of the predetermined period T.

[0086] In the end-of-period determination step 823, the acquisition unit 50 determines whether the predetermined period T has ended. If the predetermined period T ends (end-of-period determination step 823: yes), the acquisition unit 50 executes the second acquisition step 824.

[0087] In the second acquisition step 824, the acquisition unit 50 acquires the first rotational position 60 and the second rotational position 62. The first rotational position 60 acquired here represents the rotational position of the wire reel 18 at the end of the predetermined period T. The second rotational position 62 acquired here represents the rotational position of the first drum 201 at the end of the predetermined period T. After the acquisition step 82, the residual quantity estimation device 30 then performs the estimation calculation step 84.

[0088] The estimation calculation step 84 includes the ratio calculation step 841 and the residual estimation step 842 (see Figure 3).

[0089] In ratio calculation step 841, ratio calculation unit 521 calculates the first ratio α and the second ratio β. Furthermore, the first ratio α can also be calculated before the end of the predetermined period T. Therefore, the residual estimation device 30 can also start ratio calculation step 841 after the first acquisition step 822. In this case, ratio calculation step 841 can also be executed in parallel with the end-of-period determination step 823 or the second acquisition step 824.

[0090] In the residual quantity estimation step 842, the residual quantity calculation unit 522 calculates the residual quantity S of the metal wire. After the estimation calculation step 84, the residual quantity estimation device 30 then executes the comparison step 86.

[0091] In comparison step 86, the comparison unit 54 compares the estimated metal wire residual quantity S with the estimated metal wire quantity S'. If the estimated metal wire residual quantity S is less than the estimated metal wire quantity S' (86: Yes), the residual quantity estimation device 30 executes alarm generation step 88. If the metal wire residual quantity S is greater than the estimated metal wire quantity S' (86: No), the residual quantity estimation device 30 executes display step 90.

[0092] In alarm generation step 88, alarm generation unit 56 generates an alarm. The alarm is in the form of a message. This message, for example, indicates that the residual metal wire quantity S is insufficient. The residual quantity estimation device 30 then executes display step 90 after alarm generation step 88.

[0093] In step 90, the display control unit 58 displays the residual metal wire S on display screen 361. Furthermore, if alarm generation step 88 has been completed beforehand, the display control unit 58 also displays the generated alarm on display screen 361.

[0094] When performing the residual weight estimation method shown in Figure 3, the operator does not need to measure both the density and the roll radius R. This reduces the operator's workload. The above is an explanation of the residual weight estimation method shown in Figure 3.

[0095] [Variation Example] The following description is based on variations of the above-described embodiments. However, descriptions that are repeated in the above-described embodiments will be omitted as much as possible in the following description. Unless otherwise specified, the reference symbols for the constituent elements described in the above-described embodiments will be used thereafter.

[0096] (Variation Example 1) Figure 4 is a structural diagram of the residual estimation device 30 (301) according to Modified Example 1.

[0097] The residual estimation device 301 has the constituent elements of the residual estimation device 30 in the implementation state (see Figure 2). However, several constituent elements are omitted from the illustration in Figure 4.

[0098] The residual quantity estimation device 301 further includes a density calculation unit 68, a storage control unit 70, and a second estimation calculation unit 72. The density calculation unit 68, the storage control unit 70, and the second estimation calculation unit 72 are implemented by the calculation unit 42 executing the residual quantity estimation program 44. In this regard, the residual quantity estimation program 44 is appropriately modified.

[0099] Figure 5 is a schematic diagram of a metal wire spool 18 with the metal wire electrode 16 wound on it. In Figure 5, the metal wire electrode 16 and the metal wire spool 18 are shown in cross-section. Also, imagine that the straight line O is the axis of rotation of the metal wire spool 18.

[0100] The density calculation unit 68 calculates the density A based on the following mathematical formula (5). The values ​​represented by each symbol in the mathematical formula (5) are as follows: That is, "A: density". "α: first ratio". "β: second ratio". "D: wire diameter of metal wire electrode 16" (see Figure 5). "H: inner width of metal wire spool 18" (see Figure 5). "Q: spool radius". "φ: total rotation of the first spool 201".

[0101] [Formula 5]

[0102] The storage control unit 70 establishes a correspondence between the density A, wire diameter D, inner width H, and cylinder radius L. Based on this, the storage control unit 70 creates a reference table 74.

[0103] Figure 6 shows a configuration example of the reference table 74 stored in the storage section 40.

[0104] Referring to Table 74, there are rows for the identifier (name or number) of the wire spool 18, rows for density A, rows for wire diameter D, rows for inner width H, and rows for spool radius L. The information arranged horizontally in each column corresponds to each other. For example, referring to Table 74, there is an identifier for a certain wire spool 18 called "Spool 1" (see Figure 6). The density A of the wire electrode 16 wound on the wire spool 18 of "Identifier: Spool 1" is "AA". The wire diameter D of the wire electrode 16 is "DA". Also, the inner width H of the wire spool 18 of "Identifier: Spool 1" is "HA". The spool radius L of the wire spool 18 of "Identifier: Spool 1" is "LA".

[0105] Furthermore, in most cases, the wire electrode 16 is designed based on established specifications for the wire electrode 16. Therefore, the operator can easily specify the wire diameter D based on the specifications of the wire electrode 16. Also, in most cases, the wire spool 18 is designed based on established specifications for the wire spool 18. Therefore, the operator can easily specify the inner width H and the spool radius L of the wire spool 18 based on the specifications of the wire spool 18.

[0106] The storage control unit 70 stores reference table 74 in the storage unit 40. Reference table 74 is for reference by the second estimation calculation unit 72.

[0107] The second estimation calculation unit 72 estimates the residual metal wire S based on the following mathematical formula (6). The values ​​represented by each symbol in mathematical formula (6) are as follows: That is, "S: residual metal wire". "R: coil radius". "A: density". "H: inner width". "L: tube radius". "D: wire diameter". Furthermore, the density A, wire diameter D, inner width H and tube radius L correspond to each other in reference table 74. The coil radius R is measured in advance by the operator.

[0108] [Formula 6]

[0109] Table 74 contains identifiers corresponding to density A, wire diameter D, inner width H, and cylinder radius L. Thus, operators can easily specify density A, wire diameter D, inner width H, and cylinder radius L by specifying the identifiers.

[0110] Figure 7 is a flowchart illustrating the residual estimation method according to Modified Example 1. Also, the "estimation calculation steps" in Figure 3 are recorded as "first estimation calculation step" in Figure 7.

[0111] The residual estimation method in Figure 7 includes step 82, first estimation calculation step 84, comparison step 86, alarm generation step 88, and display step 90. In this respect, the residual estimation method in Figure 7 is common to the residual estimation method in Figure 3. However, the residual estimation method in Figure 7 further includes step 92, density calculation step 94, storage step 96, and second estimation calculation step 98. In this respect, the residual estimation method in Figure 7 differs from the residual estimation method in Figure 3.

[0112] The residual quantity estimation device 301 first executes selection step 92. In selection step 92, the operation unit 38 receives input operations. In selection step 92, the operator selects either the first estimation calculation step 84 or the second estimation calculation step 98.

[0113] If the operator selects the first estimation calculation step 84, the residual quantity estimation device 301 executes the acquisition step 82. Explanations of the acquisition step 82 and the first estimation calculation step 84 are omitted in this variant example. After the first estimation calculation step 84, the residual quantity estimation device 301 then executes the density calculation step 94.

[0114] In density calculation step 94, density calculation unit 68 calculates density A. Density A is calculated based on mathematical formula (5). Here, density calculation unit 68 uses the first ratio α, second ratio β, and total rotation φ used in the previous first estimation calculation step 84. Residual quantity estimation device 301 then executes storage step 96 after density calculation step 94.

[0115] In storage step 96, storage control unit 70 stores density A in storage unit 40. Here, density A corresponds to wire diameter D, inner width H, and cylinder radius L. After storage step 96, residual quantity estimation device 301 appropriately executes comparison step 86 to display step 90 (see Figure 7).

[0116] If the operator selects the second estimation calculation step 98 in step 92, the residual quantity estimation device 301 executes the second estimation calculation step 98. In the second estimation calculation step 98, the second estimation calculation unit 72 estimates the residual quantity S of the metal wire. The residual quantity S of the metal wire is calculated based on mathematical formula (6).

[0117] If the second estimation calculation step 98 is performed, the acquisition step 82 is not performed. Therefore, when the second estimation calculation step 98 is performed, it is not necessary to send out the metal wire within the predetermined period T. After the second estimation calculation step 98, the comparison steps 86 to the display steps 90 are performed appropriately (see Figure 7).

[0118] In the case of performing step 98 of the second estimation calculation, the operator measures the roll radius R beforehand. However, the operator does not need to measure the density A. This reduces the operator's workload.

[0119] The residual quantity estimation device 301 can also automatically select the second estimation calculation step 98 in the selection step 92. In this case, the operator instructs the residual quantity estimation device 301 in advance to automatically select the second estimation calculation step 98 in the selection step 92. In addition, the operator in advance specifies the density A, wire diameter D, inner width H and cylinder radius L for the second estimation calculation unit 72 to refer to.

[0120] Furthermore, the residual estimation device 301 may also perform the density calculation step 94 before the first estimation calculation step 84. In this case, the first ratio α, the second ratio β, and the total rotation amount φ can also be calculated in the density calculation step 94. In this case, the first ratio α, the second ratio β, and the total rotation amount φ can be used in the first estimation calculation step 84.

[0121] (Variation Example 2) The process of obtaining step 82 to storing step 96 in Figure 7 can also be performed on the wire reel 18 for which the density A has been previously calculated. Here, for example, the first detection signal 32 and the second detection signal 34 may contain errors (noise). Due to this error, the density A calculated in the past may be different from the density A calculated more recently. In this case, multiple density A values ​​of the same wire reel 18 are stored in the storage unit 40. However, there is only one value of density A when substituted into mathematical formula (6). Based on the above premise, in this modified example, a residual estimation device 30 (302) is described that can also calculate the residual amount S of the wire when multiple density A values ​​have been calculated for the same wire reel 18.

[0122] Figure 8 is a structural diagram of the residual estimation device 302 according to Modified Example 2.

[0123] The residual quantity estimation device 302 has the same constituent elements as the residual quantity estimation device 301 (see Figure 4). Furthermore, the residual quantity estimation device 302 also includes an averaging calculation unit 76. The averaging calculation unit 76 is implemented by the calculation unit 42 executing the residual quantity estimation program 44. Regarding this, the residual quantity estimation program 44 is appropriately modified.

[0124] The averaging calculation unit 76 calculates the average value of the complex density A. Here, the wire diameter D corresponding to the complex density A is the same for each other. Furthermore, the dimensions (inner width H, drum radius L) of the metal wire spool 18 corresponding to the complex density A are also the same for each other.

[0125] The second estimation calculation unit 72 substitutes the average value of the complex density A into the mathematical formula (6). In this way, the residual metal wire S can be estimated even when the complex density A has been calculated for the same metal wire spool 18. Furthermore, by using the average value of the complex density A for the estimation of the residual metal wire S, the influence of the aforementioned error on the estimation result of the residual metal wire S is reduced.

[0126] Furthermore, the average calculation unit 76 can also calculate the moving average of the complex density A instead of the average of the complex density A. In this case, the second estimation calculation unit 72 substitutes the moving average of the complex density A into the mathematical formula (6).

[0127] (Variation Example 3) In this variation, it is explained that the residual quantity estimation device 30 (303) notifies the operator located at a position far from the residual quantity estimation device 30 of the residual quantity S of the metal wire.

[0128] Figure 9 is a diagram of the residual estimation system 10 (101) according to Modified Example 3.

[0129] The residual estimation system 101 includes a first rotational position detection sensor 26, a second rotational position detection sensor 28, a residual estimation device 303, and an external machine 78. Descriptions of the first rotational position detection sensor 26 and the second rotational position detection sensor 28 are omitted in this variation.

[0130] External device 78 is an electronic device (terminal) capable of communicating with residual quantity estimation device 303. External device 78 has a display screen 781. External device 78 can be installed in a location remote from residual quantity estimation device 303. External device 78 can also be a portable terminal that can be carried by the operator.

[0131] The residual quantity estimation device 303 has the same components as the residual quantity estimation device 30 in the implementation state (see Figure 2). However, several components are omitted from the illustration in Figure 9.

[0132] The residual quantity estimation device 303 further includes a communication control unit 80. The communication control unit 80 is implemented by the calculation unit 42 executing the residual quantity estimation program 44. In this regard, the residual quantity estimation program 44 is modified appropriately.

[0133] The communication control unit 80 controls communication with the external machine 78. Specifically, the communication control unit 80 transmits the estimated residual metal wire quantity S to the external machine 78. The external machine 78 displays the received residual metal wire quantity S on the display screen 781. In this way, operators who are not near the residual quantity estimation device 303 can confirm the residual metal wire quantity S.

[0134] Furthermore, the communication control unit 80 can also transmit the estimation results and the comparison results with the metal wire estimation S' to the external machine 78. Additionally, the communication control unit 80 can also transmit alarms to the external machine 78.

[0135] Furthermore, the residual estimation system 101 may also have multiple external machines 78.

[0136] (Variation Example 4) The dimensions (inner width H, drum radius L) of the wire reel 18 can also be specified by the operator via the operating unit 38. For example, in most cases, the wire reel 18 is designed based on the specifications for the wire reel 18. However, there are also wire reels 18 with dimensions not based on specifications. In this case, the operator measures the dimensions of the wire reel 18. Furthermore, the operator inputs the measurement results into the residual weight estimation device 30 via the operating unit 38.

[0137] Furthermore, there are also metal wire electrodes 16 that are not based on the specifications of the relevant metal wire electrode 16. The operator can also specify the wire diameter D via the operation unit 38 when using the metal wire electrode 16.

[0138] (Variation Example 5) Alarms can take many forms, including but not limited to messages. For example, alarms can also include images. Furthermore, alarms can also include sounds (such as malfunction tones).

[0139] (Variation Example 6) A torque motor can also be connected to the wire reel 18. The torque motor is a motor used to adjust the rotational torque of the wire reel 18.

[0140] The first rotational position detection sensor 26 can also detect the rotational position of the torque motor shaft. In this case, the rotational position of the torque motor shaft is used as the first rotational position 60.

[0141] (Variation Example 7) The first ratio α and the second ratio β can also be the ratios of the rotation amount of the second roller 202 to the rotation amount of the wire reel 18, respectively. In this case, the second detection signal 34 is output in response to the rotation of the second roller 202. Furthermore, in this case, the total rotation amount φ can be the total rotation amount of the second roller 202 over a predetermined period T.

[0142] (Variation Example 8) The residual quantity estimation device 30 and the control device 24 of the wire EDM machine 12 can also be independent electronic devices.

[0143] In this case, the residual quantity estimation device 30 and the control device 24 can communicate with each other. For example, the residual quantity estimation device 30 can request the control device 24 to execute the delivery of the metal wire within a predetermined period T to perform the acquisition step 82.

[0144] Furthermore, the present invention is not limited to the above-described embodiments and variations, and various configurations may be adopted without departing from the spirit of the present invention.

[0145] [Inventions derived from their implementation] The invention described below can be derived from the above embodiments and variations.

[0146] <First Invention> A residual quantity estimation device (30, 301, 302, 303) is used to estimate the residual quantity (S) of the metal wire on the wire spool of a wire electrical discharge machining (12). The wire electrical discharge machining includes: the wire spool (18); a wire feed roller (20) for feeding the metal wire electrode (16) wound on the wire spool; a first rotational position detection sensor (26) for detecting the first rotational position (60) of the wire spool; and a second rotational position detection sensor (28) for detecting the second rotational position of the wire feed roller. The residual quantity estimation device includes: an acquisition unit (50) for acquiring the first rotation position and the second rotation position; and a first estimation calculation unit (52) for estimating the residual quantity of the metal wire at the end of the predetermined period based on the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the beginning of the predetermined period, i.e., the first ratio (α), the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the end of the predetermined period, i.e., the second ratio (β), and the total rotation amount (φ) of the wire feeding roller during the predetermined period.

[0147] This allows for the reduction of operator workload while obtaining residual metal wire (S).

[0148] The first estimation calculation unit can also estimate the residual amount of metal wire at the end of the predetermined period (T) based on the total rotation amount, the first ratio, the second ratio, the drum radius (L) of the metal wire reel, and the drum radius (Q) of the wire feeding roller.

[0149] The first estimation calculation unit can also estimate the residual amount of the metal wire based on mathematical formula (4).

[0150] The residual quantity estimation device may further include: a density calculation unit (68) that calculates the density (A) of the metal wire electrode wound on the metal wire spool based on the total rotation amount, the first ratio, the second ratio, the wire diameter (D) of the metal wire electrode, and the size of the metal wire spool; a storage control unit (70) that generates a correspondence between the density, the wire diameter, and the size of the metal wire spool and stores it in a storage unit (40); and a second estimation calculation unit (72) that estimates the residual quantity of metal wire based on the winding radius (R) of the metal wire electrode wound on the metal wire spool, the density, the wire diameter, and the size of the metal wire spool. In this way, the density (A) can be easily calculated. Furthermore, residual quantity (S) of metal wire can be saved.

[0151] The second estimation calculation unit can also estimate the density based on mathematical formula (5).

[0152] The residual quantity estimation device further includes an average calculation unit (76), which, when storing a plurality of density values ​​in the storage unit where "the corresponding wire diameter and the corresponding metal wire spool have the same size", calculates the average value or the moving average value of the plurality of density values. The second estimation calculation unit can use the average value or the moving average value as the density value to estimate the residual quantity of the metal wire. In this way, the residual quantity (S) of the metal wire can also be estimated even when a plurality of density values ​​(A) have been calculated for the same metal wire spool (18).

[0153] The residual quantity estimation device may further include an operating unit (38) that allows the operator to specify at least one of the wire diameter and the size of the wire spool. In this way, even if, for example, the size of the wire spool (18) is not in accordance with a predetermined specification, the residual quantity estimation device (30) can still estimate the residual quantity (S) of the wire.

[0154] The residual quantity estimation device may further include a display control unit (58) that displays the residual quantity of the metal wire on the display unit (36). This allows the operator to confirm the residual quantity (S) of the metal wire.

[0155] The residual quantity estimation device (303) may further include a communication control unit (80) for transmitting the residual quantity of the metal wire to an external machine (78). This allows an operator located away from the residual quantity estimation device to confirm the residual quantity (S) of the metal wire.

[0156] The residual quantity estimation device may further include an alarm generation unit (56) that generates an alarm based on the comparison between the estimated amount of metal wire (S') of the metal wire electrode required for electrical discharge machining and the residual amount of the metal wire. This can, for example, notify the operator that the residual amount of metal wire (S) is insufficient.

[0157] The residual quantity estimation device may also be included in the control device (24) that controls the wire EDM machine.

[0158] <Second Invention> A residual quantity estimation method is used to estimate the residual quantity (S) of the metal wire on the wire spool of a wire EDM machine (12). The wire EDM machine includes: the wire spool (18); a wire feed roller (20) for feeding the metal wire electrode (16) wound on the wire spool; a first rotational position detection sensor (26) for detecting a first rotational position (60) of the wire spool; and a second rotational position detection sensor (28) for detecting a second rotational position (62) of the wire feed roller. The residual quantity estimation method includes: obtaining step (82), obtaining the first rotation position and the second rotation position; and estimation calculation step (84), estimating the residual quantity of the metal wire at the end of the predetermined period based on the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the beginning of the predetermined period, i.e., the first ratio (α), the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the end of the predetermined period, i.e., the second ratio (β), and the total rotation amount (φ) of the wire feeding roller during the predetermined period.

[0159] This allows for the reduction of operator workload while obtaining residual metal wire (S).

[0160] 10: Residual Estimation System 12: Wire EDM machine 14: Wire feeding mechanism 16: Metal wire electrode 18: Metal Wire Reel 20: Wire feeding roller 201: First Roller 202: Second Roller 203: Auxiliary roller 22: Motor 221: First Motor 222: Second Motor 24: Control device 25: Metal wire conductor 26: First rotational position detection sensor 28: Second rotational position detection sensor 30, 301, 302, 303: Residual quantity estimation device 32: First detection signal 34: Second detection signal 36: Display Section 361: Display screen 38: Operations Department 40: Storage Department 42: Calculation Department 44: Residual Estimation Program 46: Processing conditions 48: Processing method 50: Acquisition Department 501: First Signal Analysis Unit 502: Second Signal Analysis Unit 52: Estimation and Calculation Department (First Estimation and Calculation Department) 521: Ratio Calculation Department 522: Residual Calculation Department 54: Comparison Section 56: Alarm Generation Department 58: Display Control Unit 60: First rotation position 62: Second rotation position 68: Denseness Calculation Section 70: Storage Control Department 72: Second Estimation and Calculation Department 74: Reference Table 76: Average Calculation Department 78: External Machines 781: Display screen 80: Communications Control Department 82: Steps to obtain 821: Initial determination steps 822: Step 1 823: End determination step 824: Step 2 84: Estimation Calculation Steps (First Estimation Calculation Step) 841: Steps for calculating the ratio 842: Residual Estimate Procedure 86: Comparison Steps 88: Alarm Generation Steps 90: Show steps 92: Select Steps 94: Steps for calculating density 96: Storage Steps 98: Second estimation calculation step W: Object to be processed L: Cylinder radius Q: Drum radius R: Roll radius H: Inner width D: wire diameter T: predetermined period TWA,TWA',TWA'':period TWB,TWB',TWB'': Period

Claims

1. A residual quantity estimation device for estimating the residual quantity (S) of a wire spool in a wire electrical discharge machining (12) comprising: a wire spool (18); a wire feed roller (20) for feeding a wire electrode (16) wound on the wire spool; a first rotational position detection sensor (26) for detecting a first rotational position (60) of the wire spool; and a second rotational position detection sensor (28) for detecting a second rotational position (62) of the wire feed roller; the residual quantity estimation device (30, 301, 302, 303) comprising: an acquisition unit (50) for acquiring the first rotational position and the second rotational position; and, The first estimation calculation unit (52) estimates the residual amount of metal wire at the end of the predetermined period based on the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the beginning of the predetermined period, i.e., the first ratio (α), the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the end of the predetermined period, i.e., the second ratio (β), and the total rotation amount (φ) of the wire feeding roller during the predetermined period.

2. The residual estimation apparatus as described in claim 1, wherein, The first estimation calculation unit estimates the residual amount of metal wire at the end of the predetermined period based on the total rotation amount, the first ratio, the second ratio, the radius of the metal wire reel (L), and the radius of the wire feeding roller (Q).

3. The residual estimation device as described in claim 2, wherein, The first estimation calculation unit estimates the residual amount of the metal wire based on the following mathematical formula (1); (where S: residual amount of metal wire, α: first ratio, β: second ratio, Q: drum radius, L: drum radius of the metal wire reel, φ: total rotation of the wire feeding drum, π: pi) [1].

4. The residual quantity estimation device (301, 302, 303) as described in any one of claims 1 to 3 further comprises: a density calculation unit (68) for calculating the density (A) of the metal wire electrode wound on the metal wire spool based on the total rotation amount, the first ratio, the second ratio, the wire diameter (D) of the metal wire electrode, and the size of the metal wire spool; a storage control unit (70) for generating a correspondence between the density, the wire diameter, and the size of the metal wire spool and storing it in a storage unit (40); and a second estimation calculation unit (72) for estimating the residual quantity of the metal wire based on the winding radius (R) of the metal wire electrode wound on the metal wire spool, the density, the wire diameter, and the size of the metal wire spool.

5. The residual estimation apparatus as described in claim 4, wherein, The second estimation calculation unit estimates the density based on the following mathematical formula (2); (where A: density of the metal wire electrode wound on the metal wire spool, α: first ratio, β: second ratio, D: wire diameter, H: inner width of the metal wire spool, Q: drum radius, φ: total rotation of the wire feeding drum) [2].

6. The residual quantity estimation device (302, 303) as described in claim 4 further includes: an average calculation unit (76) that, when the storage unit stores a plurality of densities for which the corresponding wire diameter and the corresponding size of the metal wire spool are each the same, calculates an average value of the plurality of densities or a moving average value of the plurality of densities; the second estimation calculation unit uses the average value or the moving average value as the density to estimate the residual quantity of the metal wire.

7. The residual quantity estimation device as described in claim 4 further includes: an operation unit (38) for an operator to specify at least one of the wire diameter and the size of the wire spool.

8. The residual quantity estimation device as described in any one of claims 1 to 3 further includes: a display control unit (58) for displaying the residual quantity of the metal wire on a display unit (36).

9. The residual quantity estimation device (303) as described in any one of claims 1 to 3 further includes: a communication control unit (80) for transmitting the residual quantity of the metal wire to an external machine (78).

10. The residual quantity estimation device as described in any one of claims 1 to 3 further includes: an alarm generation unit (56) that generates an alarm based on the comparison result between the estimated amount of metal wire (S') of the metal wire electrode required for electrical discharge machining and the residual amount of the metal wire.

11. The residual estimation apparatus as described in any one of claims 1 to 3, wherein, The residual quantity estimation device is included in the control device (24) that controls the wire EDM machine.

12. A residual quantity estimation method for estimating the residual quantity (S) of a wire spool in a wire electrical discharge machining (12) comprising: a wire spool (18); a wire feed roller (20) for feeding a wire electrode (16) wound on the wire spool; a first rotational position detection sensor (26) for detecting a first rotational position (60) of the wire spool; and a second rotational position detection sensor (28) for detecting a second rotational position (62) of the wire feed roller; the residual quantity estimation method comprising the following steps: an acquisition step (82) for acquiring the first rotational position and the second rotational position; and, The estimation calculation step (84) estimates the residual amount of the metal wire at the end of the predetermined period based on the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the beginning of the predetermined period, i.e., the first ratio (α), the ratio of the rotation amount of the metal wire reel to the wire feeding roller at the end of the predetermined period, i.e., the second ratio (β), and the total rotation amount (φ) of the wire feeding roller during the predetermined period.

Images