JP2019025815A - Method and apparatus for manufacturing rubber products - Google Patents

Abstract

To provide a method and an apparatus for manufacturing a rubber products capable of efficiently manufacturing rubber products of constant quality by quickly grasping a viscosity of unvulcanized rubber in a rubber product manufacturing process while making a space required for viscosity measurement compact.SOLUTION: An unvulcanized rubber R is injected from injection means 2 into a cavity 9c of a molding mold 9 through a flow path 3, and in a section of a constant cross sectional shape of the flow path 3, a pressure is detected at one detection position in this section by one pressure sensor 5, and on the basis of a detected pressure and a flow rate of the unvulcanized rubber R, or the detected pressure and a flow direction front end position of the unvulcanized rubber R and a flow velocity, a viscosity of the unvulcanized rubber R is calculated by a calculation unit 8. On the basis of a comparison between a calculated viscosity and a preset target viscosity range, an injection condition of the unvulcanized rubber R is controlled by the calculation unit 8, and the unvulcanized rubber R is molded and vulcanized by the molding mold 9.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method and an apparatus for manufacturing rubber products, and more specifically, a rubber of a constant quality by quickly grasping the viscosity of unvulcanized rubber in the manufacturing process of rubber products while making the space required for viscosity measurement compact. The present invention relates to a rubber product manufacturing method and apparatus capable of efficiently manufacturing a product.

  Rubber products include products that are produced by extruding unvulcanized rubber into a molding mold using an extruder or by using an injection machine. In addition, there is a rubber product produced by vulcanizing a molded body formed using unvulcanized rubber in a vulcanization mold. In the manufacturing process of these rubber products, the unvulcanized rubber flows to become a vulcanized rubber molded into a predetermined shape. Therefore, if the viscosity of unvulcanized rubber can be grasped and its fluidity can be predicted, it will be beneficial for quality confirmation of rubber products and productivity improvement.

  Known methods for measuring the viscosity of unvulcanized rubber include capillary rheometers (capillary viscometers), flat plate type viscometers, and the like. However, since these measurement methods are premised on measurement in a laboratory environment, the measurement results are the viscosity of unvulcanized rubber in a mold (cavity or flow path) in the manufacturing process of rubber products and the like. Is greatly different.

  Although it is a method for measuring the viscosity of a thermoplastic resin rather than unvulcanized rubber, a method for measuring the viscosity based on the pressure gradient and flow rate in the flow path of a mold for injecting the thermoplastic resin has been proposed (patent) Reference 1). However, in this proposed measuring method, two pressure sensors are required, and it is necessary to secure an installation space therefor. In order to improve the measurement accuracy, it is necessary to install the detection positions of the two pressure sensors as separated as possible. The viscosity cannot be measured unless the thermoplastic resin passes through the detection position of each pressure sensor. Therefore, in order to increase the measurement accuracy, the space required for the measuring apparatus becomes more and more. Furthermore, if the distance between the detection positions of the two pressure sensors is increased, the pressure loss in the flow path increases. Along with this, the time required for the molten resin to reach the end of the cavity from the injector becomes longer, and the risk of production defects increases. When the pressure loss of the flow path increases, there is a demerit that energy consumption increases because it is necessary to set the injection pressure high when the injection is performed in a specified time.

Japanese Patent Publication No.3-3908

  The purpose of the present invention is to produce a rubber product that can efficiently produce a certain quality rubber product by quickly grasping the viscosity of the unvulcanized rubber in the production process of the rubber product while making the space required for viscosity measurement compact. It is to provide a method and apparatus.

  In order to achieve the above object, a method for producing a rubber product according to the present invention is a method of injecting unvulcanized rubber from an injection means into a molding mold through a flow path, and molding and vulcanizing the unvulcanized rubber with the molding mold. In the manufacturing method of the product, in a section having a constant cross-sectional shape of the flow path, the section is made to flow in a state where the unvulcanized rubber is filled with one pressure sensor at one detection position of the section. The pressure is detected, and the viscosity of the unvulcanized rubber is determined based on the detected pressure and the flow rate of the unvulcanized rubber, or the detected pressure and the flow direction tip position and the flow speed of the unvulcanized rubber. The injection condition of the unvulcanized rubber is controlled based on the calculated viscosity and a comparison between the calculated viscosity and a preset target viscosity range.

  The rubber product manufacturing apparatus of the present invention includes a flow path having a section having a constant cross-sectional shape, injection means for injecting unvulcanized rubber into the flow path and filling the flow path, and In a rubber product manufacturing apparatus including a molding mold having a cavity communicating with a flow path, one pressure sensor that detects the pressure in the flow path at one detection position in the section, A flow rate detecting means for detecting the flow rate of the vulcanized rubber; and a calculation unit, wherein the section is filled with the unvulcanized rubber and is flowed to detect the pressure detected by the pressure sensor and the flow rate detecting means. The viscosity of the unvulcanized rubber is calculated by the calculation unit based on the detected flow rate, and the unvulcanized rubber is injected based on a comparison between the calculated viscosity and a preset target viscosity range. Special feature is that the conditions are controlled. To.

  Another rubber product manufacturing apparatus of the present invention includes a flow path having a section having a constant cross-sectional shape, and an injection means for injecting unvulcanized rubber into the flow path and filling the flow path. In a rubber product manufacturing apparatus comprising a molding mold having a cavity communicating with the flow path, one pressure sensor for detecting the pressure of the flow path at one detection position in the section, and in the section A tip position detecting means for detecting a tip position in the flow direction of the unvulcanized rubber, a speed detecting means for detecting a flow speed of the unvulcanized rubber, and a calculation unit, and the unvulcanized rubber in the section. Based on the detection pressure of the pressure sensor, the detection tip position of the tip position detection means, and the detection speed of the speed detection means, the calculation unit causes the unvulcanized rubber to flow. The viscosity is calculated and the calculated Based on the comparison between the target viscosity range which is set in advance with degrees, characterized in that the injection conditions of the unvulcanized rubber is configured to be controlled.

  According to the present invention, it is only necessary to detect the pressure at one detection position using one pressure sensor for the flow path for measuring the viscosity of the unvulcanized rubber. What is necessary is just to detect the flow volume of this, or the flow direction tip position and flow velocity of unvulcanized rubber. And the viscosity approximated to the viscosity in the manufacturing process of rubber products and the like can be calculated without greatly separating the pressure detection position and the detection position for detecting other data. Therefore, it is possible to quickly grasp the viscosity of the unvulcanized rubber in the rubber product manufacturing process while making the space required for the viscosity measurement compact. And by controlling the injection conditions based on the comparison between the grasped viscosity and the target viscosity range, unvulcanized rubber can be injected quickly and in an appropriate state, so it is possible to prevent the occurrence of manufacturing defects. Thus, it becomes possible to efficiently produce a rubber product of a certain quality.

It is explanatory drawing which illustrates the manufacturing apparatus of the rubber product of this invention by a longitudinal cross-sectional view. It is explanatory drawing which illustrates the molding mold of FIG. 1 by planar view. It is a graph which illustrates the relationship between the flow direction tip position of the unvulcanized rubber inject | poured into the flow path, and the pressure of a flow path. It is explanatory drawing which illustrates the state which has inject | poured the unvulcanized rubber into the flow path of FIG.

  The rubber product manufacturing method and apparatus of the present invention will be described below based on the embodiments shown in the drawings.

  A rubber product manufacturing apparatus 1 (hereinafter referred to as manufacturing apparatus 1) of the present invention illustrated in FIGS. 1 and 2 is an unvulcanized rubber R injection means 2 and the injection means 2 injects an unvulcanized rubber R. Flow path 3, a mold 9 having a cavity 9 c communicating with the flow path 3, one pressure sensor 5 for detecting the pressure P of the flow path 3, and the unvulcanized rubber R in the flow path 3. A flow rate detection means 6 for detecting the flow rate Q and a calculation unit 8 are provided. In this embodiment, the manufacturing apparatus 1 further includes a temperature sensor 7 (7a, 7b, 7c). Detection data from the pressure sensor 5, the flow rate detection means 6, and the temperature sensor 7 is input to the calculation unit 8.

  The molding mold 9 includes a core mold 9b and two divided molds 9a that are assembled vertically on the outside of the core mold 9b. A gap formed between the inner peripheral surface of each split mold 9a and the outer peripheral surface of the core mold 9b is a cavity 9c. The molding mold 9 is provided with a heating unit 10 and a temperature sensor 10a. The control unit 4 controls the heating, the heating stop, and the degree of heating of the mold 9 by the heating unit 10. The molding mold 9 is not limited to this form, and various forms can be adopted.

  The injection means 2 only needs to be able to be injected in a state where the flow path 3 is filled with the unvulcanized rubber R. For example, an extruder or an injection machine for rubber can be used. In this embodiment, as the injection means 2, a cylindrical cylinder 2a in which the unvulcanized rubber R is accommodated, a plunger 2b disposed inside the cylinder 2a, and the plunger 2b in the injection direction of the unvulcanized rubber R The extruder which has the drive mechanism 2c moved to 1 is used. The inner peripheral surface of the cylindrical portion having a constant inner diameter of the cylinder 2a and the outer peripheral surface of the cylindrical portion having a constant outer diameter of the plunger 2b face each other with almost no gap. The injection means 2 further includes a temperature adjusting unit 2d that adjusts the temperature of the unvulcanized rubber R. The operation of the drive mechanism 2c and the temperature adjustment unit 2d is controlled by the control unit 4. The control part 4 and the calculating part 8 are connected so that communication is possible.

  The channel 3 has at least a section having a certain cross-sectional shape. In this embodiment, the flow path 3 includes a linear flow path 3a extending from the tip of the cylinder 2a, and an inner peripheral surface of one split mold 7a and an outer peripheral surface of the core mold 7b connected to the flow path 3a. It is comprised by the disk shaped flow path 3b formed in the middle. The outer edge of the disk-shaped channel 3b is connected to the upper end of the cavity 9c. The inside of the cylinder 2 a and the cavity 9 c are in communication with each other through the flow path 3. The linear flow path 3a has a constant cross-sectional shape. The cross-sectional shape of the channel 3a may be a circle, an ellipse, a polygon such as a triangle, a quadrangle, or a pentagon, but a circular cross-section is preferable.

  The pressure sensor 5 detects the pressure of the flow path 3a at one detection position of the flow path 3a. That is, in the present invention, only one pressure sensor 5 is used.

  In this embodiment, the plunger 2 b is an injection moving part that moves in the injection direction of the unvulcanized rubber R and injects the unvulcanized rubber R into the flow path 3. Therefore, the flow rate detection sensor 6 detects the amount of movement of the plunger 2b per unit time in the injection direction of the unvulcanized rubber R.

  The temperature sensor 7 detects the temperature of the unvulcanized rubber R at each detection position. In this embodiment, a temperature sensor 7a that detects the temperature of the unvulcanized rubber R inside the cylinder 2a, a temperature sensor 7b that detects the temperature at the inlet (starting point of the flow path 3) of the injection means 2, and a pressure And a temperature sensor 7c that detects the temperature at a position that has passed the detection position of the sensor 5.

  A computer or the like can be used as the calculation unit 8. The calculation unit 8 receives a detection pressure P detected by the pressure sensor 5, a detection flow rate Q detected by the flow rate detection means 6, and a detection temperature T detected by the temperature sensor 7. In addition, the calculation unit 8 includes a known cross-sectional area of the plunger 2b (inner cross-sectional area of the cylinder 2a), a cross-sectional area of the flow path 3a, a length of the flow path 3a, a pressure sensor 5 and a temperature sensor in the flow path 3a. Data on the detection positions 7b and 7c (separation distances from the start point of the flow path 3a to the respective detection positions) and the target viscosity range of the unvulcanized rubber R in the flow path 3a are input. The target viscosity range is a viscosity range of the unvulcanized rubber R in the flow path 3a when a good rubber product is manufactured, and is grasped in advance.

The computing unit 8 calculates the viscosity μ of the unvulcanized rubber R based on the input detected pressure P and detected flow rate Q. A calculation formula for calculating the viscosity μ of the unvulcanized rubber R by the calculation unit 8 is the following formula (1). This equation (1) is a formula for calculating the pressure loss of the Newtonian fluid in the circular channel.
Pressure loss ΔP = (8 · μ · Q · L) / (πr ⁴ ) (1)
Here, ΔP = (pressure P ₁ at the start of the measurement section) − (pressure P ₂ at the end of the measurement section), L is the length of the measurement section, and r is the radius of the flow path 3.

In the present invention, as illustrated in FIG. 3, focusing on the fact that the pressure P _{2 of the} flow path 3 a is zero at the flow direction tip X ₂ of the unvulcanized rubber R flowing through the flow path 3 a, the pressure in the measurement section The magnitude of the loss ΔP is acquired. That is, the sensed pressure P at the detection position X ₁ of the pressure sensor 5 as P _1, the flow path 3a in the direction of flow tip X ₂ unvulcanized rubber R, which is flowing through the detection position X ₁ The pressure P is set to P ₂ = 0.

  The cylinder 2a and the flow path 3 are continuous, and the unvulcanized rubber R flows through the cylinder 2a and the flow path 3 without interruption. Since the unvulcanized rubber R can be regarded as an incompressible fluid, the flow rate Q of the unvulcanized rubber R is the volume of the section in which the plunger 2b moves within the cylinder 2a per unit time. That is, the cross-sectional area of the plunger 2b × the unit time movement amount of the plunger 2b becomes the flow rate Q. The amount of movement of the plunger 2b per unit time is detected by the flow rate detection means 6, and since the sectional area of the plunger 2b is known, the flow rate Q is known.

The front end position X ₂ of the unvulcanized rubber R in the flow direction can be calculated based on the flow rate Q. The volume (flow rate Q) of the section in which the plunger 2b moves in the unit time within the cylinder 2a is the same as the volume in which the unvulcanized rubber R moves in the unit time in the flow path 3a. Then, the flow rate Q was found, since the cross-sectional area of the passage 3a is known, the flow direction leading end position X ₂ of the unvulcanized rubber R, which flows through the flow path 3a is found. Therefore, the separation distance between the flow direction tip position X ₂ and the detection position X _1, which is the length L of the measurement section of the equation (1), is also found.

  In addition, although Formula (1) is a calculation formula applied to a circular pipe flow path, Formula (1) is arranged and used when the cross-sectional shape of the flow path 3a is other than circular.

  When the viscosity μ of the unvulcanized rubber R is calculated by the calculation unit 8, the calculation unit 8 determines whether the viscosity μ has been set via the control unit 4 based on the comparison between the calculated viscosity μ and a preset target viscosity range. The injection conditions of the vulcanized rubber R are controlled.

  Next, the procedure of the rubber product manufacturing method of the present invention will be described.

  As illustrated in FIG. 1, unvulcanized rubber R is accommodated in the cylinder 2 a of the injection means 2. At this time, the unvulcanized rubber R is heated to a predetermined temperature by the temperature adjusting unit 2d. Next, as illustrated in FIG. 4, the plunger 2 b is moved downward to inject the unvulcanized rubber R from the cylinder 2 a into the flow path 3. The unvulcanized rubber R injected into the flow path 3 flows while the flow path 3 is full. The unvulcanized rubber R that has passed through the flow path 3 is injected into the cavity 9c and molded. Thereafter, the unvulcanized rubber R is molded and vulcanized into a rubber product in the cavity 9c.

In this manufacturing process, after the unvulcanized rubber R has passed through the detection position X ₁ of the pressure sensor 5 in the flow path 3a, the detection of the pressure sensor 5 at any time prior to the unvulcanized rubber R reaches the flow path 3b The pressure P is input to the calculation unit 8. At this time, the movement amount per unit time of the plunger 2 b detected by the flow rate detection means 6 is input to the calculation unit 8.

In the calculation unit 8, the detected flow rate Q of the unvulcanized rubber R in the flow path 3a is calculated based on the input movement amount of the plunger 2b per unit time and the cross-sectional area of the plunger 2b. Further, based on the cross-sectional area of the sensing flow rate Q and the flow path 3a, the detection end position X ₂ in the flow path 3a is calculated. Since detection position X ₁ of the pressure sensor 5 is known, the distance from the starting point X ₀ of the flow path 3a to the detection end position X _2, detecting the position of the pressure sensor 5 from the starting point X ₀ of the channel 3a by subtracting the distance to the X _{1, (1)} the length L of the measurement interval in the equation is calculated.

If the pressure P ₂ of the flow path 3 at the detection end position X ₂ of the unvulcanized rubber R is zero, the pressure P ₁ of the flow path 3a of the detection position X ₁ of the pressure sensor 5 and the sensed pressure P, (1 A numerical value other than the viscosity μ in the formula is found. Therefore, the viscosity μ of the unvulcanized rubber R is calculated by the calculation unit 8 using the known data and the equation (1).

  Further, the calculation unit 8 compares the calculated viscosity μ with a preset target viscosity range. Based on the comparison result, the calculation unit 8 instructs the control unit 4 to control the injection condition of the unvulcanized rubber R. If the calculated viscosity μ is within the target viscosity range, the injection condition of the unvulcanized rubber R is maintained as it is and the injection is continued.

  When the calculated viscosity μ is lower than the target viscosity range, the injection conditions are changed so as to increase the viscosity of the unvulcanized rubber R in the flow path 3a. For example, the moving speed of the plunger 2b is increased to increase the injection pressure by the injection means 2. Alternatively, the temperature of the unvulcanized rubber R is increased by the temperature adjusting unit 2d (in some cases, in addition to the temperature adjusting unit 2d, the split mold 9a). Alternatively, the injection pressure of the unvulcanized rubber R is increased and the temperature is increased.

  When the calculated viscosity μ is higher than the target viscosity range, the injection conditions are changed so as to lower the viscosity of the unvulcanized rubber R in the flow path 3a. For example, the moving speed of the plunger 2b is slowed to lower the injection pressure by the injection means 2. Alternatively, the temperature of the unvulcanized rubber R is lowered by the temperature adjusting unit 2d (in some cases, in addition to the temperature adjusting unit 2d, the split mold 9a). Alternatively, the injection pressure of the unvulcanized rubber R is lowered and the temperature is lowered.

  When the calculated viscosity μ is significantly higher than the target viscosity range and exceeds the allowable upper limit value, or when it is extremely low and does not reach the allowable lower limit value, the unvulcanized rubber R is injected into the flow path 3a. Stop.

In the above-described embodiment, the flow rate Q of the unvulcanized rubber R is calculated based on the movement amount of the plunger 2b detected by the flow rate detection unit 6, but the flow rate detection unit 6 may be omitted. Alternatively, the temperature sensor 7b, speed detection means for detecting an unvulcanized rubber R flow velocity V of the flow direction leading end position detecting means for detecting the position X ₂ and unvulcanized rubber R of the 7c in the flow path 3a It can also be configured to function as.

  In this configuration, as illustrated in FIG. 4, when the unvulcanized rubber R is injected from the injection means 2 into the flow path 3 a, the temperature sensors 7 b and 7 c pass through the flowing unvulcanized rubber R. At this time, the detected temperature T rises rapidly. The detection positions (separation distances) of the temperature sensors 7b and 7c are known, the time point (time) at which the detection temperature T has rapidly increased can be grasped, and these data are input to the calculation unit 8. In the calculation unit 8, the flow speed V of the unvulcanized rubber R in the flow path 3 is calculated as a detection speed based on these input data.

In this configuration, the detection pressure P at the detection position X ₁ of the pressure sensor 5 is P ₁ , the detection position of the temperature sensor 7 c is the front end position X _{2 in the} flow direction, and the pressure P of the flow path 3 a is P ₂ = 0. Therefore, the detection pressure P by the pressure sensor 5 when the detected temperature T of the temperature sensor 7c is rapidly increased (when the unvulcanized rubber R has reached the detection position of the temperature sensor 7c) becomes P _1.

  Since the cross-sectional area of the flow path 3a is known, the calculation unit 8 calculates the detected flow rate Q of the unvulcanized rubber R in the flow path 3a based on this data and the calculated detection speed V. Here, since the separation distance between the detection position of the pressure sensor 5 and the temperature sensor 7c is known, this separation distance is the length L of the measurement section in the equation (1).

  As described above, numerical values other than the viscosity μ in the formula (1) are found. Therefore, the viscosity μ of the unvulcanized rubber R is calculated by the calculation unit 8 using the known data and the equation (1).

In the configuration described above, the two temperature sensors 7b and 7c that are spaced apart function as the tip position detecting means and the speed detecting means. However, one temperature sensor 7c and one pressure sensor 5 are used as the tip position detecting means and the tip position detecting means. It can also function as a speed detection means. That is, the sensed pressure P of the detection position X ₁ of the pressure sensor 5 unvulcanized rubber R through increases rapidly. The known detection position X ₁ of the pressure sensor 5, when the sensed pressure P increases rapidly (time) can be grasped.

Therefore, the pressure sensor 5 is used in place of the one temperature sensor 7b described in the configuration described above, and the other temperature sensor 7c is used in combination. Thereby, the detection tip position X ₂ and the detection speed V of the unvulcanized rubber R in the flow path 3 can be grasped. Therefore, it becomes possible to calculate the viscosity μ of the unvulcanized rubber R.

According to the various inventions described above, in order to measure the viscosity μ of the unvulcanized rubber R, the pressure is detected at _one detection position X ₁ using one pressure sensor 5 in the flow path 3a. and, in the flow path 3a to other, the flow rate Q of the unvulcanized rubber R, or may be detecting the flow direction leading end position X ₂ and velocity V of the unvulcanized rubber R. Then, a detection position X ₁ of the pressure sensor 5, the flow rate Q and the flow direction front end position X _2, may not is spaced significantly from the detection position for detecting the velocity V. Therefore, compared with the case where the pressure gradient ΔP of the flow path 3a is detected using the two pressure sensors 5, the space required for the viscosity measurement can be made compact.

  In addition, rubber molding is significantly slower in injection speed and extrusion speed than resin molding. Therefore, when two pressure sensors 5 are used, it takes a considerable time for the flowing unvulcanized rubber R to pass through the detection positions of the two pressure sensors 5. Therefore, although it is disadvantageous to quickly measure the viscosity μ of the unvulcanized rubber R, according to the present invention, such a disadvantage is avoided and the viscosity μ of the unvulcanized rubber R is quickly grasped. can do.

  When the distance between the detection positions becomes longer using the two pressure sensors 5, the pressure loss in the flow path 3a increases, and the unvulcanized rubber R reaches from the injection means 2 to the end of the cavity 9c. It takes longer time. However, in the present invention, since only one pressure sensor 5 is used, the time required for the unvulcanized rubber R to reach the end of the cavity 9c from the injection means 2 can be shortened. Therefore, it is advantageous to avoid the problem that the fluidity is lowered and the production failure occurs due to the progress of the vulcanization reaction of the injected unvulcanized rubber R. Furthermore, since the pressure loss of the flow path 3a can be reduced, when manufacturing a product in a specified time cycle, the injection pressure can be set low, so that there is an advantage that energy consumption in the manufacturing process can be suppressed.

In order to prevent manufacturing defects, it is desirable to grasp the viscosity μ as early as possible after injecting the unvulcanized rubber R into the flow path 3 and to control the injection conditions as early as possible. Therefore, the detection position X ₁ of the pressure sensor 5, as well as the position of the range from the injection port of the injection means 2 to 50% of the total length of the flow path 3, the flow rate Q or a flow direction leading end position X ₂ and fast flow rate V Is more preferably detected before the unvulcanized rubber R passes 60% of the total length of the flow path 3.

Furthermore, according to the present invention, the detection position X ₁ of the pressure P, even without greatly separated from the detection position for detecting other data, calculates a viscosity that approximates the viscosity in the manufacturing process such as rubber products be able to. That is, it is possible to calculate a viscosity that is close to the viscosity in the manufacturing process of rubber products, etc., compared with conventional viscometers such as capillary rheometers (capillary viscometers) and flat plate viscometers. Yes. It has been confirmed through experiments and simulations that the viscosity μ of the unvulcanized rubber R measured according to the present invention is closer to the viscosity in the manufacturing process of rubber products, etc. than the viscosity measured with an existing viscometer. ing.

  And the viscosity of the unvulcanized rubber R in the flow path 3a is made appropriate by controlling the injection condition of the unvulcanized rubber R based on the comparison between the calculated viscosity μ and the target viscosity range. Accordingly, the unvulcanized rubber R can be injected into the cavity 9c in an appropriate state, which is advantageous for ensuring a certain quality of the rubber product molded by the molding mold 9. Moreover, since the suitability of the viscosity μ can be quickly determined before the unvulcanized rubber R is injected into the cavity 9c, it becomes possible to prevent the occurrence of manufacturing defects and contribute to the efficient production of rubber products. To do.

  The present invention manufactures various rubber products such as tires, hoses, fenders, conveyor belts, rubber members (rubber products) constituting these rubber products, rubber manufacturing equipment members (rubber products) such as bladders, etc. Can be used when

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Injection | pouring means 2a Cylinder 2b Plunger (injection moving part)
2c Drive mechanism 2d Temperature control unit 3 (3a, 3b) Flow path 4 Control unit 5 Pressure sensor 6 Flow rate detection means 7a, 7b, 7c Temperature sensor 8 Calculation unit 9 Mold 9a Split mold 9b Core 9c Cavity 10 Heating unit R Unvulcanized rubber

Claims (8)

In a method for producing a rubber product in which unvulcanized rubber is injected from an injection means into a molding mold through a flow path, and this unvulcanized rubber is molded and vulcanized by the molding mold,
In a section having a constant cross-sectional shape of the flow path, the section is filled with the unvulcanized rubber, and the pressure is detected at one detection position in the section by one pressure sensor. The viscosity of the unvulcanized rubber is calculated based on the pressure and the flow rate of the unvulcanized rubber, or the detected pressure and the flow direction tip position and the flow speed of the unvulcanized rubber. A method for producing a rubber product, characterized in that the injection condition of the unvulcanized rubber is controlled based on a comparison between a viscosity and a preset target viscosity range.   The method for producing a rubber product according to claim 1, wherein the injection condition is at least one of an injection pressure of the unvulcanized rubber or a temperature of the unvulcanized rubber.   The detection position of the pressure sensor is set to a position in a range from the injection port of the injection means to 50% of the total length of the flow path, and the flow rate or the front end position in the flow direction and the fast flow velocity are set to the non-flow rate. The manufacturing method of the rubber product of Claim 1 or 2 detected before vulcanized rubber passes 60% of the full length of the said flow path. A mold having a channel having a section having a constant cross-sectional shape, injection means for injecting unvulcanized rubber into the channel and filling the channel, and a cavity communicating with the channel In a rubber product manufacturing apparatus comprising:
One pressure sensor for detecting the pressure of the flow path at one detection position of the section, a flow rate detecting means for detecting the flow rate of the unvulcanized rubber in the section, and a calculation unit,
Based on the detected pressure of the pressure sensor and the detected flow rate of the flow rate detecting means, the viscosity of the unvulcanized rubber is calculated by the calculation unit based on the flow of the section filled with the unvulcanized rubber. An apparatus for manufacturing a rubber product, characterized in that the injection condition of the unvulcanized rubber is controlled based on a comparison between the calculated viscosity and a preset target viscosity range.   The detection position of the pressure sensor is set to a position in a range from the injection port of the injection means to 50% of the total length of the flow path, and the flow rate of the unvulcanized rubber is equal to the total length of the flow path. The apparatus for manufacturing a rubber product according to claim 4, wherein the apparatus is detected before passing through 60%. A mold having a channel having a section having a constant cross-sectional shape, injection means for injecting unvulcanized rubber into the channel and filling the channel, and a cavity communicating with the channel In a rubber product manufacturing apparatus comprising:
One pressure sensor for detecting the pressure of the flow path at one detection position in the section, a tip position detecting means for detecting a tip position in the flow direction of the unvulcanized rubber in the section, and the unvulcanized Provided with a speed detection means for detecting the flow speed of rubber, and a calculation unit,
Based on the detected pressure of the pressure sensor, the detected tip position of the tip position detecting means, and the detected speed of the speed detecting means, the section is made to flow with the unvulcanized rubber filled. The viscosity of the unvulcanized rubber is calculated by the section, and the injection condition of the unvulcanized rubber is controlled based on a comparison between the calculated viscosity and a preset target viscosity range. Equipment for manufacturing rubber products.   The detection position of the pressure sensor is set to a position in a range from the injection port of the injection means to 50% of the total length of the flow path, and the front end position in the flow direction and the flow speed are set to the unvulcanized state. The rubber product manufacturing apparatus according to claim 6, wherein the rubber is detected before passing through 60% of the total length of the flow path.   The apparatus for producing a rubber product according to any one of claims 4 to 7, wherein the injection condition is at least one of an injection pressure of the unvulcanized rubber or a temperature of the unvulcanized rubber.

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