JP2831640B2 - Center of gravity detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] For example, using a press machine such as a synthetic rubber veil,
In a device for manufacturing a rectangular parallelepiped molded product, a half-sized product may be required at the same time as a full-sized product. For this reason, providing two sets of press machines, large and small, is economically twice as expensive and the arrangement is complicated. [Prior Art] Therefore, a cutter for manufacturing a half-size product is provided in a full-size product device series, and a full-size product is cut in half to obtain a half-size product. According to this method, the equipment cost is low, the transportation process is simple, and the efficiency is improved. [Problems to be Solved by the Invention] However, the density of the molded article is not uniform because the input of the raw materials to the press is not uniform. However, half-size products must be equal in weight,
It is not possible to cut in half by length. An object of the present invention is to provide a center-of-gravity detecting apparatus for cutting a molded article such as a rubber veil into two equal parts by applying a center-of-gravity position detecting method to such a manufacturing apparatus. [Means for solving the problem] The center of gravity detection device of the present invention, in order to achieve the above object, a feeding conveyor installed on the installation table of the weighing machine,
A servo motor for driving the conveyor, a load detector for detecting a deviation of a load between two portions in a feeding direction of a rectangular parallelepiped weighing object sent on the conveyor with respect to a weighing table center, and the load detector detects the deviation. And a control device for controlling the conveyor driving servomotor so that the deviation becomes zero. [Operation] The center of gravity detection device of the present invention is installed, for example, to detect the center of gravity when cutting a rectangular parallelepiped rubber molded product into two equal weights, and by setting the cutting position of the molded product with respect to the cutting cutter, the density is reduced. The non-uniform rubber molded product is equally divided into two weights. [Embodiment] The configuration principle of the center of gravity detection device of the present invention will be described below with reference to FIGS. In FIG. 1, the length of a full-sized rectangular parallelepiped object is L, the weight is W, the center of gravity is G, and the dimensional difference between the length center line CL and the center of gravity G is l. Now, consider a full-size product 6 divided into two blocks A and B on the right and left sides by a perpendicular passing through the center of gravity G parallel to the left and right ends. A.
B Assuming that the density is uniform in each block,
The center of gravity G ₁ · G ₂ of each block is the center of the block A · B, the weight of each block A · B is W ₁ · W ₂ , the center of gravity G of the full size product and the center of gravity G ₁ · G of each block. The distance between _{2 When, W 1 · a 1 = W} 2 · a 2 ...... (1) Thus, in the perpendicular passing through G, and cutting the dimensions article, in the illustrated example a ₁ <a ₂ Dearunode,W _1> the W _2. However, rather than halving this difference with the dimension center line CL,
It is closer to halving the weight. It is also possible to correct the deviation of the density if it is substantially constant depending on the structure of the material input. Further, if a length detector for correctly measuring the distance 1 from the dimension center CL to the center of gravity G is added to this apparatus, the correction value can be obtained closer to the true value. In FIG. 2, a true cutting position c is determined from a line passing through the center of gravity G.
The distance to is assumed to be Δl. Assuming that the density of each block A and B is constant, the portion of Δl belongs to the A block,
The weight ΔW of that part is Since it is only necessary that the weight obtained by subtracting ΔW from W ₁ is equal to the weight obtained by adding ΔW to W ₂ , When Δl is derived from this, From equation (1), From equation (5) Substituting equation (6) into equation (4) gives Here, L is a known full-size product, l is a measured value from the center position CL to the center of gravity G, and if this is input, a correction value Δl is obtained. The present invention is a center-of-gravity detecting device for providing a means for automatically stopping the center-of-gravity position G at the position of the cutter 7 in order to divide the weight into two equal parts based on the above principle. FIG. 3 shows a first embodiment, in which a roller conveyor 2 driven by a motor 1 is set on a weighing platform 3 of a weighing machine, and outputs R ₁ and R ₂ of front and rear load detectors 4 and 5 are measured. Display them separately. The distance between the load detectors 4 and 5 is L _R , the center of gravity G of the full-size product 6 sent on the weighing machine, and the center line c of the detectors 4 and 5.
Assuming that the distance from −c is X, both detectors 4.5 at that time
The difference between the outputs R _1X and R _2X is Becomes This value becomes smaller as the center of gravity G approaches the center line cc, and becomes zero when the center of gravity G coincides with the center line cc. Add control. That is, A comparator circuit that emits a signal is assembled as shown in FIG. 4, and the driving servomotor 1 is controlled. That is, the full-size product 6 is stopped at a position where the center of gravity G coincides with the center line cc. Then, the cutter 12 arranged on the line cc is lowered and cut, whereby the full-size product 6 is divided into two equal weights. Next, there are various methods for measuring the length, one example of which will be described. At a fifth figure, secure the load detector 4 and 5 the centerline c-c full size article detecting optoelectronic switch 10 at a predetermined position L ₂ of the (cutter location) from the delivery side of the before and after weighing machine, which Is the gate of the distance detection counter. Shaft encoder 11 that emits pulses equivalent to a unit length
Is connected to the roller conveyor 2 on the weighing machine, the pulse is counted by the OFF signal of the optoelectronic switch 10 (the state where the light is blocked by the article), and the counting is completed by the sending stop signal. ΔL ₂ converted from pulse number to length is the reference value
In addition to L ₂ , the length (L ₂ + ΔL ₂ ) from the center line cc of the weighing machine to the tip of the full-size product is obtained. However, if the feed control overshoots and once passes through the stop point, then reciprocates and settles to the final position, the shaft encoder 11 adopts a reversible counter method or an absolute type. There must be. Now, since the full length L of the full-size product is known, the offset position of the center of gravity G is By substituting this value into equation (7), a correction value Δl is obtained. In this way, the cutting position can be corrected, and the weight can be more accurately divided into two equal parts. However, this method uses the center of gravity G as shown in FIG.
, The density of the two parts before and after the boundary is uniform. However, usually, a density distribution d as shown in FIG.
Should be corrected, and some correction is necessary. However, the density distribution d is substantially determined by the characteristics of the equipment for feeding the raw materials to the press, and does not change randomly each time. Therefore, the weight can be corrected by separately weighing the weights of the two parts before and after cutting, taking the average of several deviations, and adjusting the correction value to Δl. In addition, this device has not only a center of gravity position detection function,
It also has a weight check function. That first whole was weighed W, feeding the portion W ₁ before or after cutting, by weighing the portion W ₂ after remaining, second portion W ₁ · W ₂ of each of the weight that can be known. This value is input to the quantitative setting device of the comparator circuit,
It is determined whether it is within the allowable range. This structure is similar to a normal weighing machine, and has a load detector R ₁
・ The sum of R ₂ should be taken. In the above description, an electric type such as an electric resistance type load cell has been described as a weight detector, but a balance may be used as a balance mechanism. An example is shown in FIG. A weighing table 15 with a feed roller conveyor is used as a balance, and a differential transformer 16 is provided at one end of the weighing table 15. When the balance is horizontal, the output of the differential transformer 16 is reduced to zero. The balance 15 is positioned on a perpendicular line cc passing through the blade 17. If the center of gravity G of the full-size product coincides with the perpendicular of the blade 17 of the balance 15, the balance is horizontally balanced, and the output of the differential transformer 16 becomes zero. Transformer 16 produces an output. With this output, the roller conveyor 2 is driven via the motor 1 to feed the object to be weighed until the balance 15 becomes horizontal, and the cutter 7 is operated. However, in this case, the weight check function cannot be incorporated. [Effect of the Invention] As described above, the present invention is applied to a case where a half-size product cut into two equal weights is economically and efficiently manufactured using a manufacturing device for a full-size product such as a rubber veil. Thus, it has a remarkable effect that a genuine equal weight bisecting position can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are explanatory diagrams of the principle of the present invention, FIG. 3 is a schematic configuration diagram of the present invention, FIG. 4 is a control block diagram of a driving servomotor of the present invention, FIG. FIG. 5 is a schematic diagram of a configuration of a molded product length measuring mechanism, FIG. 6 is an explanatory diagram of a molded product having a uniform density distribution,
FIG. 7 is an explanatory diagram of a density distribution of a molded article, and FIG. 8 is a schematic diagram of a configuration of another embodiment of the present invention. 1 ... Servo motor, 2 ... Sending conveyor, 3 ...
Weighing table, 4.5, load detector, 6 full size product, 7
... cutter, 15 ... balance, 16 ... differential transformer, 17 ... blade of balance, L ... length of full size product, G ... its center of gravity, CL
…… Central perpendicular to that length, cc …… Perpendicular to the cutter blade position.

Claims (1)

(57) [Claims] A feeding conveyor installed on the weighing platform of the weighing machine,
A servomotor for driving the conveyor, a load detector for detecting, via the weighing platform, a deviation of a load of the rectangular parallelepiped weighing object sent on the conveyor between two portions in the feeding direction with respect to the center of the weighing platform, and the load detector; A controller for controlling a servomotor for driving the conveyor so that the deviation detected by the detector becomes zero. 2. A load detector for detecting the deviation of the load is provided before and after the weighing table, and a patent is provided for separately detecting the load of the rectangular parallelepiped weighing object fed onto the conveyor in two parts before and after the feeding direction with respect to the center of the weighing table. The center of gravity detection device according to claim (1). 3. Dimension difference l between the lengthwise dimension L of the weighing object, the longitudinal center position of the weighing object, and the center of gravity G of the weighing object
From the following equation The center-of-gravity detecting device according to claim 1, wherein the position obtained by adding Δl obtained in (1) as a correction value to the dimensional difference l is a position where the object to be weighed is divided into two equal parts. 4. The center-of-gravity detecting device according to claim 1, wherein the load detector that detects the deviation of the load includes a balance and a differential transformer.