Mixing Equipment

Abstract

The objective of the present invention is to raise and lower a mixing tank to an appropriate height and to prevent trouble caused by foreign matter being caught in the mixing tank when it is raised. [Solution] The stirring device 100 is an agitation device for agitating liquids or a mixture of liquids and solids, and is characterized by comprising a stirring tank 10 with an open top, a lid portion 20 having a contact portion on one side that can contact the upper surface of the side wall of the stirring tank, a stirring tank drive unit that raises and lowers the stirring tank to an upper limit position, an intermediate position, and a lower limit position, the lid portion is supported by the stirring tank and rises and lowers only between the upper limit position and the intermediate position, a lid portion intermediate position stop unit that prevents the lid portion from descending to the lower limit position, and a pinch detection unit that detects the pinching of foreign objects between the stirring tank and the lid portion during the rise.

Description

[Technical field]

[0001] The present invention relates to an agitation device for agitating a liquid or a mixture of a liquid and a solid. [Background technology]

[0002] Agitators are used to atomize and mix liquids or mixtures of liquids and solids in cosmetics, food, chemicals, or pharmaceuticals. Agitators are composed of a roughly cylindrical mixing vessel in which a rotating blade attached to a rotating shaft rotates to mix the materials, and a drive unit for rotating the rotating shaft.

[0003] The optimal position of the mixing tank from the operator's point of view differs depending on whether the tank is in normal mixing mode, when materials to be mixed are added, or when the inside of the tank is being cleaned. For example, the optimal position of the mixing tank from the operator's perspective is considered to be at eye level for checking the mixing during normal mixing, at waist level for adding materials to be mixed, and at the operator's feet for draining the cleaning liquid inside the tank when cleaning the inside of the tank.

[0004] Patent Document 1 describes a configuration in which the inside of a stirring vessel can be observed through a viewing window provided in the lid of the stirring vessel. [Prior art documents] [Patent documents]

[0005] Patent Document 1: Patent No. 5264635 Summary of the Invention [Problem to be solved by the invention]

[0006] However, although the inside of the mixing tank can be checked through a viewing window provided in the lid at the top of the mixing tank described in Patent Document 1, the material inlet at the top of the mixing tank is above eye level, making it difficult to add materials, and there are problems with draining the cleaning solution when cleaning the inside of the mixing tank. On the other hand, when trying to raise and lower the mixing tank to the appropriate height for each task, there is a problem in that fingers or clothing may get caught in the moving parts, causing trouble.

[0007] An object of the present invention is to solve the above problems, to raise and lower a stirred tank to an appropriate height, and to prevent problems caused by foreign matter getting caught in the stirred tank when it is raised. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an agitation device for agitating a liquid or a mixture of a liquid and a solid, comprising: A mixing vessel having an open top; A lid having a contact portion on one surface thereof that can be in close contact with an upper surface of a side wall of the stirring tank; a mixing tank drive unit that raises and lowers the mixing tank to an upper limit position, an intermediate position, and a lower limit position; a lid intermediate position stopper that is supported by the mixing tank and moves up and down only between an upper limit position and an intermediate position, and prevents the lid from descending to a lower limit position; and a pinching detection unit that detects a foreign object being pinched between the stirring tank and the lid during the ascent. 、 At the lower limit position, the lid does not descend, and the mixing tank descends to open the top surface. As the mixing tank rises from the lower limit position, it approaches and comes into contact with the lid portion, which is prevented from descending at the intermediate position, and further pushes up the lid portion to rise to the upper limit position. The present invention provides a stirring device characterized by the above-mentioned.

[0009] With this configuration, the stirred tank can be raised and lowered to an appropriate height, and problems caused by foreign objects getting caught in the stirred tank when it is raised can be prevented.

[0010] In the stirring device, the entrapment detection unit may be configured to detect entrapment of a foreign object when the stirring tank rises from a lower limit position to an intermediate position and approaches the lid portion.

[0011] This configuration makes it possible to prevent a foreign object from being caught between the stirring tank and the lid from rising from the lower limit position to the intermediate position.

[0012] In the stirring device, the entrapment detection unit may be configured to detect entrapment of a foreign object when the stirring tank is raised from an intermediate position to an upper limit position while supporting the lid unit.

[0013] This configuration makes it possible to prevent a foreign object from being caught between the stirring tank and the lid from rising from the intermediate position to the upper limit position.

[0014] The stirring device may be configured such that the pinch detection unit detects that a load equal to or greater than a predetermined value is applied to the stirring tank during the upward movement.

[0015] With this configuration, it is possible to reliably detect the presence of a foreign object.

[0016] The stirring device may be configured to further include an emergency stop unit that makes an emergency stop of raising and lowering the stirring tank when the pinch detection unit detects a load equal to or greater than a predetermined value.

[0017] This configuration can prevent problems caused by foreign objects getting caught in the device. Effect of the Invention

[0018] The stirring device of the present invention makes it possible to raise and lower a stirring vessel to an appropriate height, and prevents problems caused by foreign matter becoming caught when the stirring vessel is raised. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a diagram showing the stirring vessel of the stirring device in the first embodiment of the present invention at the upper limit position. [Diagram 2] FIG. 2 is a diagram showing the stirring vessel of the stirring device in the first embodiment of the present invention in an intermediate position. [Diagram 3] FIG. 2 is a diagram showing the stirring vessel of the stirring device in the first embodiment of the present invention at the lower limit position. [Figure 4] FIG. 1 is a diagram showing a state in which an agitation tank of the agitation device in Example 1 of the present invention is overturned at a lower limit position. [Diagram 5]FIG. 2 is a first diagram illustrating a display on a display unit of the stirring device in the first embodiment of the present invention. [Figure 6] FIG. 2 is a second diagram illustrating the display of the display unit of the stirring device in Example 1 of the present invention. [Figure 7] FIG. 2 is a diagram illustrating an agitation vessel holder of the agitation device according to the first embodiment of the present invention. [Figure 8] FIG. 4 is a diagram illustrating a middle position stopper of the agitation device in the first embodiment of the present invention. [Figure 9] FIG. 4 is a diagram illustrating an upper limit position stopper of the agitation device in the first embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLES

[0020] The stirring device of the first embodiment of the present invention will be described with reference to Figs. 1-9. Fig. 1 is a diagram showing the stirring tank of the stirring device of the first embodiment of the present invention in the upper limit position. Fig. 2 is a diagram showing the stirring tank of the stirring device of the first embodiment of the present invention in the intermediate position. Fig. 3 is a diagram showing the stirring tank of the stirring device of the first embodiment of the present invention in the lower limit position. Fig. 4 is a diagram showing the stirring tank of the stirring device of the first embodiment of the present invention turned over at the lower limit position. Fig. 5 is a first diagram for explaining the display of the display unit of the stirring device of the first embodiment of the present invention. Fig. 6 is a second diagram for explaining the display of the display unit of the stirring device of the first embodiment of the present invention. Fig. 7 is a diagram for explaining the stirring tank holding unit of the stirring device of the first embodiment of the present invention. Note that the stirring blades are omitted in Fig. 7. Fig. 8 is a diagram for explaining the intermediate position stopper of the stirring device of the first embodiment of the present invention. Fig. 9 is a diagram for explaining the upper limit position stopper of the stirring device of the first embodiment of the present invention.

[0021] The stirring device 100 in the first embodiment includes a substantially cylindrical stirring tank 10 having a window 11 on the side and bottom surfaces through which the inside can be seen, and an open top surface, a substantially circular lid 20 having a contact part (not shown) made of an O-ring on one side that can be in close contact with the upper side of the side wall of the stirring tank 10, a rotating or rotating stirring blade 23 provided inside the contact part on one side of the lid 20, a material input part 21 on the other side of the lid 20, and a drive part (not shown) that raises and lowers the stirring tank 10 to an upper limit position, an intermediate position, and a lower limit position. In the first embodiment, the material stirred by the stirring blade in the stirring tank 10 is discharged into a tank or the like by tilting the stirring tank 10 sideways at the lower limit position as described later (see FIG. 4), but it may be guided to a predetermined tank through a hose (not shown) provided at the bottom of the stirring tank 10.

[0022] The stirred tank 10 in Example 1 is made of transparent glass in a substantially cylindrical shape with an open top, and has a structure in which the back surface and part of the bottom surface are supported by protective metal. Therefore, most of the front surface and bottom surface of the outer surface of the stirred tank 10 that are not protected by protective metal function as the window portion 11. In addition, the transparent glass of the stirred tank 10 is made of double glass, and hot water can be poured between the glass to increase or maintain the temperature inside the stirred tank 10, and cold water can be poured between the glass to decrease or maintain the temperature inside the stirred tank 10.

[0023] In the first embodiment, the stirring tank 10 has the window portion 11 on the side and bottom surfaces, but this is not necessarily limited to this and can be modified as appropriate. For example, the stirring tank 10 may have the window portion 11 on the side and top surface. In the first embodiment, the stirring tank 10 is made of transparent glass having a substantially cylindrical shape with an open top, but this is not necessarily limited to this and can be modified as appropriate. For example, the stirring tank 10 may be made of transparent glass having a substantially polygonal prism shape with an open top, or may be made of slightly colored glass. Furthermore, the stirring tank 10 does not have to be made of glass, and may be made of synthetic resin or stainless steel. When the stirring tank 10 is made of stainless steel, the lid portion 11 may be provided with a window portion through which the inside can be seen.

[0024] Furthermore, from the upper limit position to the intermediate position, the contact portion of the lid portion 20 is in contact with the agitation tank 10, so the agitation blade 23 can be rotated or turned to agitate the inside of the agitation tank 10, and the inside of the agitation tank 10 can be evacuated. However, in order for the contact portion of the lid portion 20 to come into contact with the agitation tank 10, the agitation tank 10 needs to be pressed against the contact portion of the lid portion 20 to such an extent that the O-ring constituting the contact portion is deformed. Therefore, as described below, after the agitation tank 10 rises and comes into contact with the contact portion of the lid portion 20, the agitation tank 10 can be further raised and pushes up the lid portion 20, so that the agitation tank 10 and the lid portion 20 can be reliably brought into contact with each other.

[0025] In Example 1, the lid part 20 is configured to be in close contact with the stirred tank 10 from the upper limit position to the intermediate position, but this is not necessarily limited to this and can be modified as appropriate. For example, the lid part 20 may be configured to be in close contact with the stirred tank 10 only at the upper limit position and the intermediate position, or the close contact part of the lid part 20 may be configured to be in close contact with the upper surface of the side wall of the stirred tank 10 at least at the upper limit position and the intermediate position.

[0026] A rubber O-ring is provided on one surface of the lid 20 (the surface that contacts the top surface of the agitation tank 10) of the lid 20, so that the lid 20 can be fitted tightly to the upper surface of the side wall of the agitation tank 10. From the upper limit position to the intermediate position, the upper surface of the side wall of the agitation tank 10 is pressed against and fitted tightly to the fitting part of the lid 20, and the agitation blade 23 provided on one surface of the lid 20 (the surface that contacts the top surface of the agitation tank 10) rotates or turns within the agitation tank 10 to agitate the charged materials.

[0027] In this way, the lid 20 and the agitation tank 10 are configured to be able to come into close contact with each other, and may rise from the intermediate position to the upper limit position while still in close contact. Therefore, if clothing or the like is caught between the lid 20 and the agitation tank 10 for some reason before rising and rises in this state, it may lead to an accident. For this reason, as described below, there is provided a pinching detection unit (not shown) that detects that a foreign object has been caught between the lid 20 and the agitation tank 10, and an emergency stop unit (not shown) that makes an emergency stop of the agitation tank 10 when the pinching detection unit detects that a foreign object has been caught. This stops the agitation tank 10 from rising while the foreign object is caught, and prevents trouble from occurring.

[0028] A rotation drive unit 22 that rotates or turns the stirring blade 23 is provided on the other surface of the lid unit 20. The rotation drive unit 22 moves up and down integrally with the lid unit 20 as described below.

[0029] The agitation tank 10 is held by the agitation tank holder 50 (see FIG. 7), and can be raised and lowered along the rail 40, which is fixed to the rail holder 43 and extends up and down, by driving a drive unit consisting of a motor and a trapezoidal screw (not shown). The worker H raises and lowers the agitation tank 10 to the upper limit position by touching the touch panel labeled "upper limit" in a box labeled "continuous operation" on the display unit 30 shown in FIG. 5. Similarly, the agitation tank 10 raises and lowers to the middle position by touching "middle". Furthermore, the agitation tank 10 descends to the lower limit position by touching "lower limit". The position of the top surface of the agitation tank 10 shown in FIG. 1 is the upper limit position set at 1533 mm from the floor surface, and is a position where the worker H can visually check the inside of the agitation tank 10 through the window 11 to check the agitation state. In addition, at this upper limit position, the agitation state in the agitation tank 10 can be checked from the window 11 at the bottom of the agitation tank 10.

[0030] In Example 1, the upper limit position is the distance from the floor surface to the top surface of the mixing tank 10 of 1533 mm, but is not necessarily limited to this and can be changed as appropriate. For example, it may be 1534 mm or more or 1532 mm or less, and may be set at a position where the operator H can easily view the inside of the mixing tank 10 through the window portion 11. To change the upper limit position, the "upper limit position for lifting" in FIG. 5 may be changed, or the position of the upper limit position stopper 42 (see FIG. 9) may be adjusted as described below.

[0031] The position of the top surface of the mixing tank 10 shown in Fig. 2 is an intermediate position set at 962 mm from the floor surface. This intermediate position is set at a position where operator H can easily input materials into the material input section 21. Note that the inside of the mixing tank 10 may be evacuated. In this case, after inputting materials into the hopper of the material input section 21, the cock is turned to open the door to the inside of the mixing tank 10, and the materials are drawn in by the vacuum. After this, in order to maintain the vacuum state, the cock is turned in the opposite direction to close the door to the inside of the mixing tank 10, and the evacuated state of the mixing tank 10 is maintained.

[0032] In Example 1, the intermediate position is the distance from the floor surface to the top surface of the mixing tank 10 of 962 mm, but this is not necessarily limited to this and can be changed as appropriate. For example, it may be 963 mm or more or 961 mm or less, and may be set at a position where the operator H can easily input material into the material input section 21. To change the intermediate position, the "lift intermediate position" in FIG. 5 may be changed.

[0033] The position of the top of the agitation tank 10 shown in Fig. 3 is the lowest position set at 622 mm from the floor. At this lowest position, the top of the agitation tank 10 is open, allowing the inside of the agitation tank 10 to be visually observed. In other words, the lid part 20, together with the drive part 22, is held in the middle position by the middle position stopper 41 (see Fig. 8) and will not descend to the lowest position. As a result, the lid part 20 is released from its tight contact with the top of the agitation tank 10, and the top is opened.

[0034] In Example 1, the lower limit position is the distance from the floor surface to the top surface of the mixing tank 10 of 622 mm, but this is not necessarily limited to this and can be changed as appropriate. For example, it may be 623 mm or more or 621 mm or less, and may be set at a position where the operator H can easily visually inspect and clean the inside of the mixing tank 10. To change the lower limit position, the "lifting / lowering limit position" in FIG. 5 may be changed.

[0035] 4, at the lowest position, the stirring tank 10 can be tilted sideways, and the inside of the stirring tank 10 can be washed to remove residue and the like. Also, washing water can be poured into the stirring tank 10 for washing.

[0036] When the agitation tank 10 is raised from the lowest position to the intermediate position, the agitation tank 10 is raised and reaches the intermediate position by touching the area marked "Intermediate" (see FIG. 5) in the box marked "Continuous Operation" on the touch panel of the display unit 30. The agitation tank 10 can then be stopped temporarily at the intermediate position. At this time, when the distance between the agitation tank 10 and the lid unit 20 falls within a predetermined range during the ascent of the agitation tank 10, the rate of ascent is slowed down. This makes it possible to prevent the agitation tank 10 from colliding with the lid unit 20 too forcefully and breaking the glass, if the agitation tank 10 is made of glass.

[0037] To slow down the ascent Meno The predetermined range is set to 20 mm in the first embodiment, but can be changed by setting the value of "speed change distance near lid contact" shown in Fig. 5. Also, the speed during deceleration can be set by setting the value of "rising speed when lid contacts".

[0038] In order to prevent fingers or clothing from being caught between the rising mixing tank 10 and the lid 20 and thus causing injury or damage to clothing, a pinch detection unit (not shown) that detects pinching when a load equal to or greater than a predetermined value is detected, and an emergency stop unit that controls the mixing tank 20 to make an emergency stop when the pinch detection unit detects pinching of a foreign object, are provided. In the first embodiment, in order to detect a load equal to or greater than a predetermined value, the pinch detection unit monitors the torque value when the mixing tank 10 is rising. Then, pinching of a foreign object is detected by detecting a torque equal to or greater than a predetermined value. This predetermined torque value can be set by setting the value of the "torque limit under lid contact" in FIG. 5.

[0039] As described above, the pinch detection unit also functions when the lid 20 and the stirring tank 10 are in close contact with each other and rise from the intermediate position to the upper limit position. The predetermined value of the torque when the stirring tank 10 rises from the intermediate position to the upper limit position may be the same as the predetermined value when the stirring tank 10 rises from the lower limit position to the intermediate position, or may be set separately.

[0040] If a foreign object such as a finger or clothing becomes caught between the rising mixing tank 10 and the lid 20, as shown in Figure 6, the message "Torque Limit ON" will be displayed and the emergency stop unit will halt the rise of the mixing tank 10, preventing troubles such as injury or damage to clothing.

[0041] After the agitation tank 10 comes into contact with the lid 20, the agitation tank 10 is further raised, pushing the lid 20 up by about 10 mm. The rising speed at this time can be set by setting the value of the "rising speed when the lid comes into contact" shown in FIG. 5. By pushing the tank 10 up further after the contact, the upper surface of the side wall of the agitation tank 10 and the contact part of the lid 20 can be tightly attached to each other. By tightly attaching the agitation tank 10 and the lid 20, the agitation blade 23 is stored in the agitation tank 10 even at the intermediate position, so that the agitation can be performed by rotating or turning. A vacuum can also be drawn.

[0042] In Example 1, the stirring tank 10 is further raised after contact with the lid portion 20, so that the lid portion 20 is pushed up by about 10 mm, but this is not necessarily limited to this and can be modified as appropriate. For example, the stirring tank 10 may be pushed up by about 20 mm, or may be pushed up by about 5 mm. It is sufficient that at least the contact portion of the lid portion 20 and the upper surface of the side wall of the stirring tank 10 are in close contact with each other.

[0043] When the agitation tank 10 is raised from the intermediate position to the upper limit position, the agitation tank 10 is raised to the upper limit position by touching the area marked "upper limit" (see FIG. 5) in the box marked "continuous operation" on the touch panel of the display unit 30. At this time, as the agitation tank 10 rises, the agitation tank holder 50 pushes up the rotation drive unit holder 60 holding the lid unit 20 and the rotation drive unit 22 while the agitation tank 10 is in close contact with the lid unit 20, and the agitation tank 10, the lid unit 20, and the rotation drive unit 22 rise together to the upper limit position (see FIG. 8). In other words, only the agitation tank holder 50 holding the agitation tank 10 is driven by the agitation tank drive unit, and the rotation drive unit holder 60 holding the lid unit 20 and the rotation drive unit 22 is pushed up by the agitation tank holder 50 holding the agitation tank 10. This allows the agitation tank 10 and the lid unit 20 to maintain a close contact state.

[0044] The lifting and lowering speed of the mixing tank 10 can be changed by changing the value displayed as "Lifting and lowering operation speed (normal)" on the touch panel of the display unit 30. Specifically, when "Lifting and lowering operation speed (normal)" is touched, a numeric keypad pops up, and a number is entered.

[0045] Next, the positioning of the lid part 20 and the rotary drive part 22 at the upper limit position and the intermediate position will be described in detail with reference to Figs. 7 to 9. In Fig. 7, the illustration of the agitation blade part 23 is omitted. Here, Figs. 8 and 9 are views seen from the rear side. As described above, it is the agitation tank holder 50 that holds the agitation tank 10 that is raised and lowered by the agitation tank drive part (not shown) consisting of a trapezoidal screw and a motor. In this way, the agitation tank 10 held by the agitation tank holder 50 can be raised and lowered. In addition, the lid part 20 and the rotary drive part 22 are held by the rotary drive part holder 60.

[0046] In addition, when the mixing tank 10 and the mixing tank holding part 50 are in the intermediate position and the lowermost position, the rotation drive unit holding part 60 stops at the intermediate position as the intermediate position stopper block 61 at the bottom of the rotation drive unit holding part 60 comes into contact with the intermediate position stopper 41 fixed to the rail holding part 43, and the rotation drive unit holding part 60 cannot descend any further.

[0047] When the mixing tank holder 50 rises from the lower limit position to the intermediate position, the push-up portion 51 of the mixing tank holder 50 pushes up the push-up portion corresponding block 63 of the rotation drive unit holder 60 a little. Then, the upper surface of the side wall of the mixing tank 10 comes into contact with the contact portion of the lid unit 20. Next, when the mixing tank holder 50 rises from the intermediate position to the upper limit position, the push-up portion 51 of the mixing tank holder 50 pushes up the push-up portion corresponding block 63 of the rotation drive unit holder 60, so that the mixing tank 10, the lid unit 20, and the rotation drive unit 22 rise together. When the mixing tank 10 rises to the upper limit position, the upper limit position stopper block 62 fixed to the rotation drive unit holder 60 comes into contact with the upper limit stopper 42 and stops. Then, the mixing tank 10 cannot rise any further.

[0048] When the mixing tank holder 50 descends from the upper limit position, the mixing tank 10 and the lid 20 remain in close contact with each other, and the mixing tank 10 held by the mixing tank holder 50 also begins to descend. In other words, the rotation drive unit holder 60, whose pushing-up force of the mixing tank holder 50 has been released, descends together with the mixing tank holder 50, and at the same time, the lid 10 and the rotation drive unit 22 also descend together. When the mixing tank holder 50 descends to the intermediate position and stops, the intermediate position stopper block 61 fixed to the rotation drive unit holder 60 comes into contact with the intermediate position stopper 41 supported by the rail holder 43, and it cannot descend any further.

[0049] When the stirring tank holder 50 descends further from the intermediate position, the contact between the lid part 20 and the upper surface of the side wall of the stirring tank 10 is released, and the lid part 20 and the rotary drive part 22 remain in the intermediate position, while only the stirring tank 10 and the stirring tank holder 50 descend to the lowest position, thereby releasing the contact between the stirring tank 10 and the lid part 20. When the stirring tank 10 descends to the lowest position and is separated from the lid part 20, the inside of the stirring tank 10 can be easily cleaned. Furthermore, the stirring blade 23 is exposed from the stirring tank 10, so that the stirring blade 23 can also be easily cleaned.

[0050] Thus, in Example 1, A mixing device for mixing a liquid or a mixture of a liquid and a solid, comprising: A mixing vessel having an open top; A lid having a contact portion on one surface thereof that can be in close contact with an upper surface of a side wall of the stirring tank; a mixing tank drive unit that raises and lowers the mixing tank to an upper limit position, an intermediate position, and a lower limit position; a lid intermediate position stopper that is supported by the mixing tank and moves up and down only between an upper limit position and an intermediate position, and prevents the lid from descending to a lower limit position; This mixing device is characterized by being equipped with a pinch detection unit that detects whether or not a foreign object has become pinched between the mixing tank and the lid while the mixing tank is being raised, making it possible to raise and lower the mixing tank to an appropriate height and to prevent problems caused by foreign objects becoming pinched when the mixing tank is being raised. [Industrial Applicability]

[0051] The stirring device of the present invention can be widely applied to fields in which liquids or mixtures of liquids and solids are stirred. [Explanation of symbols]

[0052] 10: Mixing tank 11: Window section 20: Lid section 21: Material input section 22: Rotation drive section 23: Mixing blade 30: Display section 40: Rail 41: Intermediate position stopper 42: Upper limit position stopper 43: Rail holding section 50: Mixing tank holding section 51: Push-up section 60: Rotation drive section holding section 61: Intermediate position stopper block 62: Upper limit position stopper block 63: Push-up section corresponding block 100: Mixing device

Claims

1. A mixing device for mixing a liquid or a mixture of a liquid and a solid, comprising: A mixing vessel having an open top; A lid having a contact portion on one surface thereof that can be in close contact with an upper surface of a side wall of the stirring tank; a mixing tank drive unit that raises and lowers the mixing tank to an upper limit position, an intermediate position, and a lower limit position; a lid intermediate position stopper that is supported by the mixing tank and moves up and down only between an upper limit position and an intermediate position, and prevents the lid from descending to a lower limit position; a pinching detection unit that detects a foreign object being pinched between the stirring tank and the lid during the upward movement, At the lower limit position, the lid does not descend, and the mixing tank descends to open the top surface. The stirring device is characterized in that, as the stirring tank rises from a lower limit position, it approaches and comes into contact with the lid portion, which is prevented from descending at an intermediate position, and further pushes up the lid portion to rise to an upper limit position.

2. 2. The mixing device according to claim 1, wherein the pinch detector detects pinching of a foreign object when the mixing tank rises from a lower limit position to an intermediate position and approaches the lid.

3. 2. The agitation device according to claim 1, wherein the pinch detection unit detects pinching of a foreign object when the agitation tank is raised from an intermediate position to an upper limit position while supporting the lid unit.

4. The mixing device according to any one of claims 1 to 3, characterized in that the pinch detection unit detects that a load of a predetermined value or more is applied to the mixing tank while it is being raised or lowered.

5. 5. The mixing device according to claim 4, further comprising an emergency stop unit that makes an emergency stop of raising and lowering the mixing tank when the pinch detection unit detects a load equal to or greater than a predetermined value.

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