CN108357010B

CN108357010B - Door for opening and closing discharge port of rubber mixing mill

Info

Publication number: CN108357010B
Application number: CN201810074183.XA
Authority: CN
Inventors: 东孝祐; 福谷和久; 山根泰明; 宫坂和夫; 植村正昭
Original assignee: Kobe Steel Ltd
Current assignee: Kobe Steel Ltd
Priority date: 2017-01-26
Filing date: 2018-01-25
Publication date: 2020-06-23
Anticipated expiration: 2038-01-25
Also published as: DE102018101540B4; CN108357010A; JP2018118510A; DE102018101540A1; JP7002343B2

Abstract

The invention provides a door for opening and closing a discharge port of a rubber mixing mill, which can inhibit rubber as a mixing object from being involved in a rotor. The gate (32) opens and closes a discharge port (37) formed in the bottom of the chamber (31) of the rubber kneading machine (100), and the side inserted into the chamber (31) is formed in a laterally symmetrical mountain shape. In a cross section orthogonal to the longitudinal direction, the mountain-shaped outer shape (1) of the door (32) is a first arc (1a) which is recessed downward from a door lower end corner (32a) contacting the inner opening end of the outlet (37) toward the door top (32b) which is the highest in the vertical direction to the halfway portion, a straight line (1b) which is inclined with respect to the horizontal direction from the halfway portion, and a second arc (1c) which is recessed downward further to the door top (32 b).

Description

Door for opening and closing discharge port of rubber mixing mill

Technical Field

The present invention relates to a door provided at a discharge port formed at the bottom of a chamber of a rubber kneading machine and opening and closing the discharge port.

Background

Examples of such doors include doors described in patent documents 1 and 2.

The door (discharge door) described in patent document 1 has a shape determined as follows. Lines (L) connecting the contact points (D, E) of the discharge port and the discharge gate of the closed mixing chamber and the rotation centers (A, B) of the kneading rotors₁)、(L₂) The centers (Q) of the radii (S) are respectively arranged. Arcs passing through the contacts (D, E) are drawn with the center (Q) as a fulcrum. The intersection of the arcs is defined as the front end (P) of the discharge gate. The tip of the discharge gate is shaped so that when an arc of radius (R) is drawn with the center of rotation (O) of the discharge gate as a fulcrum, the tip (P) does not interfere with the contact (D) and the tip of the rotating kneading rotor, and the center (Q) is as close as possible to the centers of rotation (A) and (B) of the kneading rotors.

Patent document 1 describes the following: the discharge gate having the above-described shape can effectively knead the compound in the closed mixing chamber, and even when the compound which is easily in close contact with the mixing chamber is kneaded, the compound can be simply and effectively discharged without being entirely discharged and being sandwiched between the peripheral edge of the discharge port and the discharge gate or adhering to the gap between the peripheral edge of the discharge port and the discharge gate when the compound is discharged.

The door (drop door) described in patent document 2 has a shape defined as follows, and the ratio α (═ h/R) between the height h of the drop door and the radius R of the chamber is set to 0.6 ≦ α ≦ 0.8.

Patent document 2 describes the following: the drop door having the above-described shape can improve the mixing and dispersing action in the kneading chamber, and can obtain a uniform kneaded product in a short time. Further, since the space formed by the upper part of the drop door and the rotor is also reduced, the retention, fixation, and the like of the compounding agent and the kneaded material are also reduced.

Prior art documents

Patent document

Patent document 1: japanese patent No. 2562396

Patent document 2: japanese laid-open patent publication No. 8-332630

Disclosure of Invention

Problems to be solved by the invention

In some cases, a sheet-shaped rubber (rubber sheet) is fed into a rubber kneader as a material to be kneaded and kneaded. The rubber sheet may be wound around a rotor (kneading rotor) in a solid state (sheet state) at the initial stage of charging the rubber sheet into the chamber.

In both of the gates described in patent documents 1 and 2, the inclined surface on the kneading chamber side in contact with the rubber is a smooth and continuous curved surface. In the door described in patent document 2, a small portion of the top is a straight line extending in the horizontal direction. In the case of a door having such a shape, adhesion of rubber to the door can be suppressed. However, when the material to be kneaded is a rubber sheet, it is difficult for the rubber to remain in the gate portion. Therefore, the winding of the rubber into the rotor is easily generated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a door capable of opening and closing a discharge port of a rubber kneading machine while suppressing the entrainment of rubber to be kneaded into a rotor.

Means for solving the problems

The present invention provides a door for opening and closing a discharge port of a rubber mixing mill, which opens and closes the discharge port formed at the bottom of a chamber of the rubber mixing mill, and one side inserted into the chamber is formed into a bilaterally symmetrical mountain shape, wherein in a cross section orthogonal to a longitudinal direction, the mountain shape has an outer shape of a first arc which is recessed downward from a lower end corner of the door contacting an inner opening end of the discharge port toward a door top portion which is highest in a vertical direction to a middle portion, and a second arc which is recessed downward from the middle portion to the door top portion.

Effects of the invention

According to the door having the above-described structure, the rubber can be retained to some extent in the vicinity of the door in the chamber, and thereby the entanglement of the rubber into the rotor can be suppressed.

Drawings

Fig. 1 is a cross-sectional view of a rubber kneading machine including a gate according to an embodiment of the present invention.

Fig. 2 is a view showing an outer shape (mainly, only one side) of a mountain-shaped portion of a door according to a plurality of embodiments including the door shown in fig. 1.

Fig. 3 is a graph showing a CV value ratio of a door having a shape according to the embodiment of the present invention with respect to a door having a conventional shape.

FIG. 4 is a diagram for explaining a method of drawing a door profile (straight line) in the range of 0. ltoreq. x.ltoreq.0.65L.

FIG. 5 is a diagram for explaining a drawing method of a door profile (arc) in the range of 0.825L ≦ x ≦ L.

Fig. 6 is a cross-sectional view of a longitudinal center portion of the door according to the embodiment of the present invention.

Fig. 7 is a cross-sectional view of the door according to the embodiment of the present invention, taken along the longitudinal direction.

Description of the reference numerals

1 to 8 shape

1 a-8 a first arc

1b to 8b straight line

1 c-8 c second arc

31 chamber

32 door

32a door lower corner

32b door top

37 discharge port

38 recess

40 thermometer

100 rubber mixing mill

Detailed Description

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(construction of rubber kneading machine)

The structure of a rubber kneading machine 100 including a gate 32 according to an embodiment of the present invention will be described with reference to fig. 1. The rubber to be kneaded by the rubber kneader provided with the gate of the present invention is not limited to rubber (rubber sheet) having a sheet shape.

The rubber kneading machine 100 is a device for kneading rubber as a material to be kneaded, and includes a supply unit 20 and a kneading unit 30. The supply unit 20 is a part that supplies the material to be kneaded to the kneading unit 30, and includes a hopper 21, a material supply cylinder 22, and a cylinder device 23.

The rubber (material to be kneaded) to be kneaded is fed from the outside of the rubber kneader 100 to the hopper 21. The material supply cylinder 22 is a cylinder through which the material to be kneaded can pass. The upper part of the material supply cylinder 22 communicates with the hopper 21.

The cylinder device 23 is a device for pressing the material to be kneaded from the material supply cylinder 22 into the kneading section 30 (a kneading chamber 33 described later). The cylinder device 23 is, for example, a pneumatic actuator. The cylinder device 23 includes a cylinder 24, a piston 25, a piston rod 26, and a floating weight 27.

The floating weight 27 connected to the lower end of the piston rod 26 is a member for pressing the material to be kneaded, which is fed from the hopper 21, into the kneading chamber 33.

The kneading section 30 is a section for kneading materials to be kneaded, and includes a chamber 31, a gate 32 for opening and closing (opening and closing) a discharge port 37 formed in the bottom of the chamber 31, and a pair of rotors 34 and 35 (kneading rotors).

The chamber 31 is a portion in which a kneading chamber 33 is formed, and a supply port 36 for a material to be kneaded is provided at an upper portion thereof. The floating weight 27 is lowered from above the supply port 36 toward the supply port 36.

The kneading chamber 33 is a space for kneading the materials to be kneaded. The longitudinal cross-sectional shape of the kneading chamber 33 is an eyebrow shape. The vertical cross-sectional shape is a cross-sectional shape of the kneading chamber 33 when viewed from the axial direction of the rotors 34 and 35.

The door 32 is driven by an actuator to open and close the discharge port 37 of the chamber 31. The discharge port 37 of the chamber 31 is closed by the gate 32 during the kneading of the material to be kneaded, and the gate 32 is opened when the rubber (kneaded material) having been kneaded is discharged from the chamber 31. The actuator that drives the door 32 is, for example, a rotary actuator (rotary actuator). The gate 32 (gate shape) greatly affects the degree of kneading of the rubber kneaded by the rotors 34 and 35 in the chamber 31 (in the kneading chamber 33).

The rotors 34 and 35 are members for kneading the materials to be kneaded, and are disposed in the chamber 31 (in the kneading chamber 33). The rotors 34, 35 rotate about their central axes. Fig. 1 shows the center of rotation C of the rotors 34, 35. The rotors 34 and 35 rotate in different directions from each other so that the facing portions move downward.

(shape of door)

The door 32 will be described in detail. The side of the door 32 inserted into the chamber 31 is formed in a mountain shape. The mountain shape is a bilaterally symmetrical shape in a cross-section orthogonal to the longitudinal direction of the door 32.

See, for example, the portion of door 32 in fig. 1 and outline 1 in fig. 2. In the door 32 according to the embodiment of the present invention, in a cross-section orthogonal to the longitudinal direction, the mountain-shaped outer shape 1 is a first arc 1a recessed downward from a door lower end corner 32a contacting the inner open end of the outlet 37 toward the door top 32b that is the highest in the vertical direction up to the halfway portion, a second arc 1c recessed downward from the halfway portion up to the door top 32b and a straight line 1b inclined with respect to the horizontal direction. That is, the outer shape 1 of the mountain-shaped portion of the door 32 is formed by the first arc 1a, the straight line 1b, and the second arc 1c in this order from the door lower end corner 32a toward the door top 32b between the door lower end corner 32a and the door top 32 b. Fig. 2 is a cross-sectional view of the door orthogonal to the longitudinal direction, showing the outer shape (mainly, only one side) of the mountain-shaped portion of the door. The one-dot chain line in fig. 2 is a center line.

Fig. 2 shows a total of eight door shapes from the outer shape 1 to the outer shape 8 according to the embodiment of the present invention. As shown in FIG. 2, in the outer shapes 1 to 8, the first arcs 1a to 8a, the straight lines 1b to 8b, and the second arcs 1c to 8c are formed between the door lower corner 32a and the door top from the door lower corner 32a toward the door top. Note that the outer shape of the door (the eccentric door) shown by the broken line labeled "prior art" in fig. 2 is a curved surface that is smoothly continuous throughout except for the top of the door. Note that a small portion of the top of the prior art door is a straight line extending in the horizontal direction.

The present inventors evaluated the total of eight gates having the outer shapes 1 to 8 shown in fig. 2 and the gate having the conventional shape shown in fig. 2 with respect to the entrainment of the rubber into the rotors 34 and 35, the influence on the degree of kneading of the rubber, and the adhesion of the rubber to the gate. The evaluation results are shown in table 1. The rubber as the material to be kneaded is a rubber (rubber sheet) having an initial form (form at the time of charging) and a sheet form.

[ TABLE 1 ]

Door with a door panel	Roll in	To mixingInfluence of degree	Attachment of
				Prior Art	×	-	○
Outer shape 1	○	◎	○
				Outer shape 2	○	◎	○
Outer shape 3	○	×	×
				Outer shape 4	○	◎	○
Outer shape 5	○	×	○
				Outer shape 6	○	○	○
Outer shape 7	○	○	×
				Outer shape 8	○	◎	△

[ description of Table 1 ]

Roll-in ○ has roll-in inhibiting effect

× the product has no rolling-in inhibiting effect

Mixing degree of ◎: Excellent

○ good

× difference

Attachment ○ No attachment

△ attachment according to fit

× there is always an attachment

[ concerning the winding-in of rubber ]

In contrast to the conventional art in which the inclined surfaces on the kneading chamber 33 side in contact with the rubber are all smoothly continuous curved surfaces, in the gate of the present invention, as in the external shapes 1 to 8 shown in fig. 2, the inclined surfaces on the kneading chamber 33 side in contact with the rubber are formed as first arcs 1a to 8a recessed downward from the gate lower end corner 32a toward the gate top portion to the halfway portion, as straight lines 1b to 8b inclined from the halfway portion to the horizontal direction, and then second arcs 1c to 8c recessed downward further to the gate top portion 32b, and by the presence of the straight lines 1b to 8b portions between the arcs (1a to 8a, 1c to 8c), the rubber can be retained to a certain extent in the vicinity of the gate in the cavity 31 (in the kneading chamber 33), and thus the eight gates of the external shapes 1 to 8 have the effect of suppressing the rubber, while the effect of the conventional art is not shown in table 3583.

[ Effect on kneading degree ]

FIG. 3 is a graph showing CV value ratios of the doors having the outer shapes 1 to 8 of the embodiment of the present invention shown in FIG. 2 to the doors having the conventional shape shown in FIG. 2. Here, the CV value is an index by which the distribution mixing progress of the rubber can be judged as the smaller the value. The CV value ratio is a CV value (ratio of CV values) of each gate when the CV value of the gate having the conventional shape shown in fig. 2 is 1. The smaller the CV value ratio means, the more improved the distributive mixing of the rubber. Fig. 3 is a graph showing a CV value ratio after 10 rotations of rotors 34 and 35 when flow analysis is performed on nine gates in total including the prior art.

As can be seen from fig. 3, the doors having improved CV values by 10% or more as compared with the doors (eccentric doors) having the prior art shape are four doors of the outer shape 1, the outer shape 2, the outer shape 4, and the outer shape 8, and the doors having improved CV values by less than 10% are two doors of the outer shape 6 and the outer shape 7, and it is noted that the two doors of the outer shape 3 and the outer shape 5 have slightly deteriorated CV values as compared with the doors having the prior art shape, and these results are shown by ◎, ○, and × in table 1.

[ adhesiveness to rubber ]

The adhesion of rubber to each gate was evaluated by flow analysis of a total of nine gates including the prior art. As shown in table 1, no adhesion of rubber was observed in the doors having the conventional shapes and the doors having the outer shapes 1, 2, 4 to 6 according to the embodiment of the present invention. In the door having the outer shape 8 according to the embodiment of the present invention, adhesion of rubber was observed depending on the blend of rubber. It was found that rubber was always adhered to each of the doors of the outer shapes 3 and 7 according to the embodiment of the present invention.

[ regarding a more preferable door shape ]

As described above, in the cross-sectional view orthogonal to the longitudinal direction, the outer shape of the mountain shape is a first arc that is recessed downward from the gate lower end corner portion 32a toward the gate top portion to the halfway portion, a straight line that is inclined with respect to the horizontal direction from the halfway portion, and a second arc that is recessed downward further to the gate top portion, whereby the rubber can be retained to some extent in the vicinity of the gate in the chamber 31 (in the kneading chamber 33), and the entrainment of the rubber into the rotors 34 and 35 can be suppressed.

<1. door capable of suppressing the entanglement of rubber, preventing the adhesion of rubber and improving the distributive mixing of rubber >

A more preferable shape of the door will be described with reference to fig. 2, 4, and 5. Here, in a cross-section orthogonal to the longitudinal direction, the door lower end corner 32a is set as the origin O, the horizontal direction is set as the x-axis, and the direction from the door lower end corner 32a toward the door top in the horizontal direction is set as the positive x-axis (see the x-axis arrow in fig. 4 and 5). The vertical direction is defined as the y-axis, the direction from the door lower end corner 32a toward the door top in the vertical direction is defined as the positive y-axis (see the arrow on the y-axis in fig. 4 and 5), and the horizontal distance between the origin O and the door top is defined as L. In the shapes 1-8, the range of x being more than or equal to 0 and less than or equal to 0.65L is respectively set as an arc 1 a-8 a, the range of x being more than or equal to 0.65L and less than or equal to 0.825L is set as a straight line 1 b-8 b, and the range of x being more than or equal to 0.825L and less than or equal to L is set as an arc 1 c-8 c.

Regarding the adhesion of rubber, the influence of the shape of the door in the range of 0. ltoreq. x.ltoreq.0.65L is large. The shape of the door in the range of 0.65L. ltoreq. x.ltoreq.0.825L has a smaller influence than the shape of the door in the range of 0. ltoreq. x.ltoreq.0.65L, but slightly affects the adhesion of rubber. On the other hand, distribution mixing (kneading) of rubber is greatly influenced by the shape of the gate top side (the range of 0.825L. ltoreq. x. ltoreq.L) of the gate. Thus, the mountain-shaped region of the gate in the range of 0.825L ≦ x ≦ L is a region where the distributive mixing of the rubber is improved.

According to table 1, with respect to the outer shape of the mountain-shaped portion of the door which can suppress the entanglement of the rubber and is less likely to adhere the rubber and improve the distribution mixing of the rubber, the outer shape in the range of 0. ltoreq. x.ltoreq.0.65L is a first arc of constant curvature passing through the region satisfying the following expression (1), the outer shape in the range of 0.65L. ltoreq. x.ltoreq.0.825L is a straight line inclined with respect to the horizontal direction passing through the region satisfying the following expression (2), and the outer shape in the range of 0.825L. ltoreq. x.ltoreq.l is a second arc of constant curvature passing through the region satisfying the following expression (3). It should be noted that, although the details will be described later, when the x-coordinate of the center point of the second arc is p, p < 0.825L is also required.

θ: an inclination angle of a tangent line at an origin O of a circle having a radius R passing through the origin O with respect to the horizontal direction centered on a rotation center C of a rotor of the rubber kneading machine 100 (see fig. 4);

r: the radius of a circle passing through the origin O with the rotation center C of the rotor of the rubber kneading machine 100 as the center (see fig. 4), and the radius of the circular portion of the inner wall surface of the chamber 31 (see fig. 1).

The left circular arc expression in expression (1) is a circular arc expression in which a part of a circle is indicated by a solid line having a center S1 and a radius of 0.76R shown in fig. 4, and the right circular arc expression in expression (1) is a circular arc expression in which a part of a circle is indicated by a solid line having a center S2 and a radius of 0.63R shown in fig. 4. The center S1 of the circle indicated by the solid line having the radius 0.76R is the upper point of two intersections between a straight line perpendicular to the tangent line at the origin O of the circle having the radius R passing through the origin O with the rotation center C of the rotor as the center and a circle indicated by the broken line having the radius 0.76R with the origin O as the center. The center S2 of the circle indicated by the solid line having the radius 0.63R is the upper point of two intersections between a straight line perpendicular to the tangent line at the origin O of the circle having the radius R passing through the origin O with the rotation center C of the rotor as the center and a circle indicated by the broken line having the radius 0.63R with the origin O as the center.

The left arc formula in formula (1) is the first arc formula including the outer shapes 6, 7, 8, 6a, 7a, 8a (see fig. 2), and the right arc formula in formula (1) is the first arc formula including the outer shapes 1, 2, 3, 1a, 2a, 3a (see fig. 2).

The left-hand linear expression in equation (2) represents a straight line 6b (see fig. 2) of the outer shape 6, and the right-hand linear expression in equation (2) represents a straight line 1b (see fig. 2) of the outer shape 1.

R: the radius of a circle passing through the origin O with the rotation center C of the rotor of the rubber kneading machine 100 as the center (see fig. 5), and the radius of the circular portion of the inner wall surface of the chamber 31 (see fig. 1);

l 1: x coordinates of a lower point P1 having an inclination tan (θ +124) and a lower point P1 out of two intersection points of a circle having a radius of 0.99R and a straight line x passing through the gate top, the circle being centered on the rotation center C of the rotor, and an upper point Q1 out of two intersection points of a circle having a radius of 0.16R and centered on the lower point P1 (see fig. 5);

m 1: a y-coordinate of a lower point P1 having an inclination tan (θ +124) and a straight line L1 passing through a lower point P1 of two intersection points of a circle having a radius of 0.99R and a straight line x passing through the gate top centered on the rotation center C of the rotor and an upper point Q1 of two intersection points of a circle having a radius of 0.16R and centered on the lower point P1 (see fig. 5);

l 2: x-coordinate of a lower point P2 having an inclination tan (θ +124) and a straight line L2, which passes through a circle having a radius of 1.05R and a straight line x passing through the gate top L, which passes through the center C of the rotor, and an upper point Q2, which passes through a circle having a radius of 0.43R and which passes through the lower point P2 (see fig. 5);

m 2: a y-coordinate of a lower point P2 having an inclination tan (θ +124) and a straight line L2 passing through a lower point P2 of two intersection points of a circle having a radius of 1.05R and a straight line x passing through the gate top, the circle being centered on the rotation center C of the rotor, and an upper point Q2 of two intersection points of a circle having a radius of 0.43R and centered on the lower point P2 (see fig. 5);

θ: an inclination angle of a tangent line at an origin O of a circle having a radius R passing through the origin O with respect to the horizontal direction centered on a rotation center C of a rotor of the rubber kneading machine 100. In addition, m1 is not less than 0.65L, m2 is not less than 0.65L, y is not less than m 1.

The straight line x ═ L passing through the gate top is also a perpendicular bisector of a line segment connecting the centers of the two rotors 34 and 35.

The left circular arc expression in expression (3) is a partial circular arc expression of a circle indicated by a center Q2(l2, m2) and a solid line with a radius of 0.43R shown in fig. 5, and the right circular arc expression in expression (3) is a partial circular arc expression of a circle indicated by a center Q1(l1, m1) and a solid line with a radius of 0.16R shown in fig. 5. The left arc formula in formula (3) is an arc formula including a second arc 6c (see fig. 2) of the outer shape 6, and the right arc formula in formula (3) is an arc formula including a second arc 1c (see fig. 2) of the outer shape 1.

Here, in the door of profile 3, the distribution mixing of the rubber was deteriorated (refer to table 1). This is considered to be because the midway portion of the second arc 3c is recessed (lowered) from the end (x is 0.825L) of the second arc 3c on the gate lower end corner portion 32a side, and therefore rubber stagnation occurs there, which leads to deterioration in rubber distribution and mixing. Therefore, when the shape is obtained such that the middle portion of the second arc is not recessed from the end (x is 0.825L) of the second arc on the door lower end corner portion 32a side, it is necessary to make p < 0.825L when the x-coordinate of the center point of the second arc is p, such as the outer shape 4 (second arc 4 c).

<2 > door capable of suppressing the entanglement of rubber, preventing the adhesion of rubber, and further improving the distributive mixing of rubber

According to table 1, the outer shape of the mountain-shaped portion of the door, which can suppress the entrainment of the rubber, hardly adheres to the rubber, and further improve the distribution mixing of the rubber, is the first arc of constant curvature that further passes through the region satisfying the following expression (4) in the outer shape of the range of 0 ≦ x ≦ 0.65L, the straight line that further passes through the region satisfying the following expression (5) and is inclined with respect to the horizontal direction in the outer shape of the region 0.825L ≦ x ≦ L, and the second arc of constant curvature that further passes through the region satisfying the following expression (6).

θ and R in formula (4) are the same as those in formulae (1) and (2).

The left arc expression in expression (4) represents an arc expression of a part of a circle indicated by a solid line having a center S1 and a radius of 0.71R shown in fig. 4, and the right arc expression in expression (4) represents an arc expression of a part of a circle indicated by a solid line having a center S2 and a radius of 0.63R shown in fig. 4. The center S1 of the circle represented by the solid line having the radius 0.71R is the upper point of two intersections between a straight line perpendicular to the tangent line at the origin O of the circle having the radius R passing through the origin O with the rotation center C of the rotor as the center and a circle represented by the broken line having the radius 0.71R centered on the origin O. The center S2 of the circle indicated by the solid line having the radius 0.63R is the upper point of two intersections between a straight line perpendicular to the tangent line at the origin O of the circle having the radius R passing through the origin O with the rotation center C of the rotor as the center and a circle indicated by the broken line having the radius 0.63R with the origin O as the center.

The left arc formula in formula (4) is an arc formula including first arcs 4a and 5a (see fig. 2) of outer shapes 4 and 5, and the right arc formula in formula (4) is an arc formula including first arcs 1a, 2a, and 3a (see fig. 2) of outer shapes 1, 2, and 3.

θ and R in formula (5) are the same as those in formulae (1) and (2).

The left-hand linear expression in equation (5) represents a straight line 4b (see fig. 2) of the outer shape 4, and the right-hand linear expression in equation (2) represents a straight line 1b (see fig. 2) of the outer shape 1.

R, l1 and m1 in formula (6) are the same as R, l1 and m1 in formula (3).

l 3: x-coordinate of a lower point P2 having an inclination tan (θ +80) and a lower point P3 of two intersection points of a circle having a radius of 1.05R and a straight line x passing through the gate top L, the circle being centered on the rotation center C of the rotor, and an upper point Q3 of two intersection points of a circle having a radius of 0.43R and the lower point P2 (see fig. 5);

m 3: a y-coordinate of a lower point P2 having an inclination tan (θ +80) and a straight line L3 passing through a lower point P2 of two intersection points of a circle having a radius of 1.05R and a straight line x passing through the gate top, the circle being centered on the rotation center C of the rotor, and an upper point Q3 of two intersection points of a circle having a radius of 0.43R and centered on the lower point P2 (see fig. 5);

θ: an inclination angle of a tangent line at an origin O of a circle having a radius R passing through the origin O with respect to the horizontal direction centered on a rotation center C of a rotor of the rubber kneading machine 100. In addition, m1 is not less than 0.65L, m3 is not less than 0.65L, y is not less than m 1.

The straight line x ═ L passing through the gate top is also a perpendicular bisector of a line segment connecting the centers of the two rotors 34 and 35. The left arc formula in formula (6) is an arc formula including a second arc 4c (see fig. 2) of the outer shape 4, and the right arc formula in formula (6) is an arc formula including a second arc 1c (see fig. 2) of the outer shape 1.

(thermometer mounting to door)

The installation of the thermometer 40 to the door 32 will be described with reference to fig. 6 and 7. As shown in fig. 6 and 7, the center portion in the longitudinal direction of the door top portion 32b is a recessed portion 38. A hole 39 is opened in the recess 38, and a thermometer 40 is inserted into the hole 39 and fixed (installed). The recess 38 is partially formed into a curved surface as shown in fig. 6.

In a cross-section orthogonal to the longitudinal direction, the mountain-shaped outer shape 1 of the door 32 at a portion other than the recess 38 is formed by a first arc 1a, a straight line 1b, and a second arc 1c over the entire length of the door 32 in the longitudinal direction. The thermometer 40 is provided so as not to protrude upward beyond the door top 32 b.

According to the above configuration, it is possible to prevent rubber from adhering to the vicinity of the door 32 where the thermometer 40 is provided.

(modification example)

In the door of the embodiment shown in fig. 2, the outer shape changes from a circular arc to a straight line at a position of 0.65L from the door lower end corner portion 32a to the door top portion in the horizontal direction, and changes from a straight line to a circular arc at a position of 0.825L. The position of the change from the circular arc to the straight line may be slightly shifted from the position of 0.65L. The position of the arc from the straight line may be slightly shifted from the position of 0.825L.

Claims

1. A door for opening and closing a discharge port of a rubber kneading machine, which opens and closes a discharge port formed in the bottom of a chamber of the rubber kneading machine, and has a laterally symmetrical mountain shape on the side inserted into the chamber,

in a cross-sectional view orthogonal to the longitudinal direction, the mountain-like shape has an outer shape of a first arc which is recessed downward from a corner portion of the lower end of the door which is in contact with the inner open end of the outlet toward the vertically highest door top portion to a middle portion, a straight line which is inclined with respect to the horizontal direction from the middle portion, and a second arc which is recessed downward further to the door top portion.

2. The door for opening and closing the discharge port of a rubber kneading machine according to claim 1,

when the door lower end corner portion is set to an origin, a horizontal direction is set to an x-axis, a direction from the door lower end corner portion toward the door top portion in the horizontal direction is set to positive of the x-axis, a vertical direction is set to a y-axis, a direction from the door lower end corner portion toward the door top portion in the vertical direction is set to positive of the y-axis, and a distance between the origin and the door top portion in the horizontal direction is set to L, the outer shape in a range of 0. ltoreq.x.ltoreq.0.65L is set to the first circular arc of a certain curvature passing through a region satisfying formula (1), the outer shape in a range of 0.65L. ltoreq.x.ltoreq.0.825L is set to the straight line passing through a region satisfying formula (2), and the outer shape in a range of 0.825L. ltoreq.l is set to the second circular arc of a certain curvature passing through a region satisfying formula (3) in a cross-section orthogonal to the longitudinal direction,

wherein the x coordinate p of the central point of the second circular arc is p < 0.825L,

θ: an inclination angle of a tangent line at the origin of a circle passing through the origin with respect to a horizontal direction centered on a rotation center of a rotor of a rubber kneading machine;

r: a radius of a circle passing through the origin with a rotation center of a rotor of the rubber kneading machine as a center, and a radius of a circular portion of an inner wall surface of the chamber;

l 1: x coordinates of an upper point of two intersection points of a straight line having a slope of tan (θ +124) and passing through a lower point of two intersection points of a circle having a radius of 0.99R and passing through a straight line x ═ L passing through the gate top centered on the rotation center of the rotor, and a circle having a radius of 0.16R centered on the lower point;

m 1: y coordinates of a point above, out of two intersection points of a circle having a radius of 0.99R and a straight line having a slope of tan (θ +124), the circle having a center of rotation of the rotor as a center, and a straight line having a slope of tan (θ +124), the circle having a radius of 0.16R, the straight line passing through the gate top portion as a lower point;

l 2: x coordinates of an upper point of two intersection points of a straight line having a slope of tan (θ +124) and passing through a lower point of two intersection points of a circle having a radius of 1.05R and passing through the center of rotation of the rotor and a straight line x passing through the gate top portion of L, and a circle having a radius of 0.43R and passing through the lower point;

m 2: and y coordinates of a lower point of two intersection points of a circle having a radius of 1.05R and a straight line x passing through the gate top, the circle having a center of rotation of the rotor, and a circle having a radius of 0.43R, the straight line having an inclination of tan (θ + 124).

3. The door for opening and closing the discharge port of a rubber kneading machine according to claim 2,

the outline of the range of 0. ltoreq. x.ltoreq.0.65L is set as the first circular arc further passing through a certain curvature of the region satisfying formula (4), the outline of the range of 0.65L. ltoreq. x.ltoreq.0.825L is set as the straight line further passing through the region satisfying formula (5), and the outline of the range of 0.825L. ltoreq. x.ltoreq.L is set as the second circular arc further passing through a certain curvature of the region satisfying formula (6),

l 3: x coordinates of an upper point of two intersection points of a straight line having a slope of tan (θ +80) and passing through a lower point of two intersection points of a circle having a radius of 1.05R and passing through the center of rotation of the rotor and a straight line x passing through the gate top portion equal to L, and a circle having a radius of 0.43R and passing through the lower point;

m 3: and y coordinates of a lower point of two intersection points of a circle having a radius of 1.05R and a straight line x passing through the gate top, the circle having a center of rotation of the rotor, and a circle having a radius of 0.43R, the straight line having an inclination of tan (θ + 80).

4. The door for opening and closing the discharge port of a rubber kneading machine according to any one of claims 1 to 3,

the central portion in the longitudinal direction of the door top is provided as a concave portion,

a thermometer is arranged in the concave part,

the mountain-shaped outer shape of the portion other than the concave portion is formed by the first arc, the straight line, and the second arc in a cross-section orthogonal to the longitudinal direction.