JP4949868B2 - Centrifuge door mechanism - Google Patents

Description

  The present invention relates to a door mechanism of a centrifuge that separates a liquid sample such as blood using centrifugal force.

  As a door mechanism of a centrifuge, for example, a door mechanism described in Patent Document 1 is known. The door mechanism of the centrifuge described in Patent Document 1 is configured to open and close the door using a gas spring. When the door is opened, the gas spring extends to push the door upward. When it is lifted and opened substantially vertically, the stroke ends. According to such a door mechanism, when the door is lifted vertically upward, the weight in the gravity direction of the door can be reduced by the extending action of the gas spring, so that the door can be opened with a slight force. When the door is opened vertically upward, the gas spring functions as a stay, so that generation of vibration and noise can be prevented. In addition, if the torque hinge that pivots the door is given rotational resistance in accordance with the turning operation, the rotation that is applied to the torque hinge even if the gas spring causes a gas outage failure and loses its extension force. It is said that there is no risk of the door suddenly turning and dropping due to its own weight due to resistance, and safety can be improved.

  Further, in the conventional door mechanism of this type of centrifuge, as shown in FIGS. 6 and 7, a stopper rubber 2 is attached to the upper rear portion of the housing 1 via an attachment fitting 3, and the door 4 is substantially vertical. When opened upward, the back surface of the door 1 is received and supported by the stopper rubber 2 so as to determine the fully open position vertically above the door 4. In addition, 5 is a gas spring and 6 is a hinge.

JP 2005-34724 A

  However, in the conventional centrifuge door mechanism shown in FIGS. 6 and 7, the stopper rubber 2 and the mounting bracket 3 constitute a protrusion protruding rearward of the housing 1. In addition to the poor appearance of the centrifuge, there are problems that when the centrifuge 10 is carried, the operator's hand or part of the body hits the stopper rubber 2 or the mounting bracket 3 or the clothes are caught. It was.

  Further, the conventional stopper rubber 2 receives the weight of the door 4 on the entire upper surface when the door 4 is fully opened, so that a large compressive force is applied, and it is easily deformed or deteriorated. The material rubber had to be used. In particular, if the durability is lost, there is a problem that when the door 4 is opened, the door 4 is vibrated (oscillated) and vibration sound associated therewith easily occurs.

  Furthermore, since the stopper rubber 2 is bonded to the mounting bracket 3 with an adhesive in the assembly work of the door mechanism, it is necessary to wait for the next work until the adhesive is cured, and the assembly work takes a long time. There was also a problem.

  Further, when the mounting bracket 3 is fixed to a predetermined position on the back surface of the housing 1 with a plurality of set screws 7, if the mounting position of the mounting bracket 3 is shifted, a difference in the opening angle of the door 4 or a swing is likely to occur. There was also a problem of becoming.

  Furthermore, since the conventional door mechanism stops the door 4 at the open position at the stroke end of the gas spring 5, if the door 4 swings, the gas spring 5 may be damaged, resulting in an outgassing accident. . The gas spring 5 loses its supporting force to the door 4 completely when an outgassing accident occurs. Therefore, the door 4 is suddenly rotated and dropped by its own weight, and the operator's hand is sandwiched between the housing 1 and the door 4. There was a risk of it.

  The present invention has been made in order to solve the above-described conventional problems. The purpose of the present invention is to prevent the stopper member from protruding outside the housing, and to improve the appearance, handling and safety of the centrifuge. Another object of the present invention is to provide a door mechanism for a centrifuge capable of improving the durability and the like of a stopper member and reducing and preventing the vibration of the door.

In order to achieve the above object, the present invention provides a casing that opens upward, a chamber that accommodates a rotor that is disposed in the casing and that centrifuges a sample, and is attached to an upper surface opening of the casing. A centrifuge comprising: a top plate covering an outer periphery of the housing; and a door attached to a rear upper end edge of the housing via a hinge so as to be freely opened and closed, and covering a top opening of the housing. A gas spring that is disposed and opens the door vertically upward during an extension operation; and a stopper member made of an elastic material attached to the gas spring; and a hole for stay through which the gas spring penetrates the upper surface plate. provided, wherein the gas spring comprises a cylinder body which compressed gas is filled, a piston rod projecting from the cylinder body, and in any of the extended state and shorten state Maintaining a state inclined rearward, said cylinder body through said stay hole during expansion operation is intended to protrude above the casing, the stopper member, the cylinder body is formed in a cylindrical body Is fitted to the outer periphery of the upper end of the stay hole with the lower surface of the upper surface plate as the gas spring extends. As a result, the contact area with the upper surface plate increases, and the extension operation of the gas spring is stopped immediately before the stroke end.

According to a second aspect of the present invention, in the door mechanism of the centrifugal separator according to the first aspect, the structure for positioning the lower end of the stopper member with respect to the cylinder body is an annular groove formed on the outer peripheral surface of the cylinder body. The stopper member is mounted on the retaining ring via the support washer, and has a structure having a retaining ring fitted to the retaining ring and a support washer stacked on the retaining ring. A centrifugal stopper member is formed in a cylindrical body and is supported by a gas spring.

  In the present invention, since the door is opened and closed using the gas spring, the door can be opened and closed with a slight force, and the handleability of the centrifuge can be improved.

  Since the stopper member is attached to the gas spring, the stopper member does not constitute a protrusion protruding outside the housing, and the appearance of the centrifuge can be improved.

  Further, the stopper member comes into contact with the lower surface of the upper surface plate as the door is opened, and is pressed while gradually increasing the contact area. Therefore, deformation and deterioration can be reduced, and durability can be improved. That is, the amount of deformation is reduced by gradually reducing the force per unit area applied to the stopper member. Deterioration (sagging) is reduced by reducing the amount of deformation. In addition, if the durability is improved, an elastic member made of an inexpensive material can be used. Further, if there is little deformation or deterioration, the door vibration can be reduced.

  Furthermore, the stopper member is pressed against the top plate and compressed to stop the gas spring extending immediately before the end of the gas spring stroke end, so that the opening angle of the door can be made constant and the gas can be made constant. The spring will not cause a gas outage accident.

Further, the present invention forms a stopper member to the cylindrical body, is supported by a gas spring, because they fit the gas spring stopper member in loosely, the upper plate by the rotation of the stopper member is hit at a fixed position The durability of the stopper member is improved. In addition, the stopper member can be easily and easily attached.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 is a cross-sectional view of a centrifuge having a door mechanism according to the present invention in a state where the door is open, and FIG. 2 is a side view showing a part of the centrifuge when the door is closed. 3 is a plan view of the casing of the centrifuge, FIG. 4 is a side view showing a state in which the gas spring is extended, and FIGS. 5A to 5C are views showing changes in the contact area of the stopper member with respect to the top plate. It is.

  1 to 3, the centrifuge generally indicated by reference numeral 20 is a rectangular parallelepiped casing 21 that opens upward, a door 22 that covers the upper surface of the casing 21, and the casing 21. A centrifuge rotor 24 housed in the chamber 23, a drive motor 25 that rotates the rotor 24 at a high speed during centrifugation, a door mechanism 26 that opens and closes the door 22, and the like. ing.

  The front plate 21 </ b> A of the casing 21 has an upper portion inclined forward and downward, and a switch panel 30 is provided on the inclined portion. The switch panel 30 is provided with a start button, various buttons for setting centrifugation conditions (time, rotation speed, etc.), an LED display device, and the like.

  An upper surface plate 31 that covers the periphery of the chamber 23 is disposed on the upper surface of the housing 21. The upper surface plate 31 is formed with an opening 32 having the same size as the inner diameter of the chamber 23 and a pair of left and right stay holes 33. The stay holes 33 are long holes in the front-rear direction, and are formed at both side edges on the rear end side of the top plate 31. An annular edge rubber 34 that is in close contact with the outer peripheral edge of the upper surface of the chamber 23 when the door 22 is closed is attached.

  When the door 22 is closed, the door 22 is locked to the housing 21 by being engaged with an engaging portion (not shown) provided on the housing 21 side when the door 22 is closed. A pair of left and right hooks 35 are attached.

  The centrifuge rotor 24 includes a cross-shaped support arm 37 attached to the rotary shaft 36 of the drive motor 25 and a support shaft (trunion pin) 38 on each arm portion of the support arm 37. It is composed of a swing rotor provided with four buckets 39 loaded with a plurality of sample tubes 40 that are rotatably mounted and contain a liquid sample. However, the centrifuge rotor 24 is not limited to a swing rotor and may be an angle rotor.

The door mechanism 26 includes a hinge 42 that pivotally connects the rear end of the door 22 to the upper edge of the back plate 21B of the housing 21 and a pair of left and right gas springs 43 that open and close the door 22. . Each gas spring 43 includes a cylinder main body 43A filled with compressed gas, and a piston rod 43B that is slidably fitted into the cylinder main body 43A and has one end protruding outward. It is each arrange | positioned along the inner surface of a side plate. The gas spring 43 has a piston rod 43B on the lower side and a cylinder body 43A on the upper side. The lower end of the piston rod 43B is attached to a bracket 44 provided on the inner bottom surface of the housing 21 in the front-rear direction via a connecting pin 45. A bracket pivotally attached to the cylinder body 43A so that the cylinder body 43A passes through the stay hole 33 of the upper surface plate 31 and protrudes upward from the housing 21, and the protruding end protrudes from the rear rear end of the door 22. It is pivotally attached to 46 via a connecting pin 47. Further, the gas spring 43 is shortened to the minimum when the door 22 of FIG. 2 is closed. As shown in FIG. 1, the gas spring 43 is extended by the gas pressure in the cylinder main body 43A when the door 22 is opened. Is raised, the door 22 is pushed up, and is configured to open in a substantially vertical state. Note that the gas spring 43 is held in an inclined state in both the extended state and the shortened state, and a stopper member 50 described later comes into contact with the lower surface of the upper surface plate 31. .

  Furthermore, the cylinder body 43A of the gas spring 43 is provided with the stopper member 50 for setting the upper limit of the cylinder body 43A, a support washer 51 and a retaining ring 52 (see FIG. 4) for positioning the lower end of the stopper member 50, respectively. It is installed. The stopper member 50 is formed in a cylindrical body whose both ends are opened by an elastic material such as rubber, for example, a general chloroprene rubber having a hardness of 60 ° to 70 °, and is fitted in the outer periphery of the cylinder body 43A in a loosely fitted state. Has been. Further, the stopper member 50 is compressed by being gradually pressed against the peripheral portion of the stay hole 33 on the lower surface of the upper surface plate 31 in accordance with the extending operation of the gas spring 43, as shown in FIG. The contact area S with the upper surface plate 31 gradually increases as indicated by the oblique lines in FIG. 5C, and the elastic force due to compression becomes equal to the extension force of the gas spring 43 immediately before the gas spring 43 reaches the stroke end. Thus, the extension operation of the gas spring 43 is stopped, and the door 22 is stopped at the open position opened at the maximum angle. The opening angle of the door 22 can be changed by changing the length and hardness of the stopper member 50, changing the mounting position with respect to the cylinder body 43A, or changing the number of the support washers 51 and the fixing position of the retaining ring 52. An arbitrary opening angle can be set. The retaining ring 52 is fitted into an annular groove formed on the outer peripheral surface of the cylinder main body 43 </ b> A, and a stopper member 50 is placed thereon via a support washer 51.

  In the centrifuge 20 having such a structure, in order to start the centrifuge operation, the rotor 24 having the sample tube 40 mounted in the chamber 23 is inserted into the chamber 23 and fixed to the rotating shaft 36 of the drive motor 25. To do. Next, in order to change the door 22 from the opened state to the closed state, the operator pushes and closes the outer surface of the door 22 by hand. At this time, the gas spring 43 is shortened and the gas pressure in the cylinder body 43A is increased. For this reason, the extension force of the gas spring 43 becomes stronger as the door 22 is closed, and the door 22 is prevented from suddenly dropping. If the extension force of the gas spring 43 is set slightly larger than the weight of the door 22 itself, the door 22 can be closed without requiring a large force. After the door 22 is locked and preparation is completed, the drive motor 25 is driven to rotate the rotor 24 at a high speed, and the sample in the sample tube 40 is centrifuged.

  When the centrifugation operation of the sample by the centrifuge 20 is completed, the operator operates the open button of the operation panel 30 to take out the rotor 24 or the sample tube 40 from the chamber 23. Then, the locked state of the door 22 is released, the gas spring 43 is driven and extended, and the door 22 is pushed up. For this reason, the door 22 is gradually rotated upward about the axis of the hinge 42 by the extending action of the gas spring 43 and opened. When the gas spring 43 is extended, the stopper member 50 is also raised along with the extension operation of the gas spring 43, and when the gas spring 43 is raised to a certain height, both upper side portions of the stopper member 50 are pressed against the lower surface of the upper surface plate 31 and compressed. The contact area S with the upper surface plate 31 gradually increases. When a certain amount of compression is performed, the resilience is resisted against the extension force of the gas spring 43, and the extension operation of the gas spring 43 is stopped immediately before the gas spring 43 reaches the stroke end. For this reason, the door 22 also stops and is held in a state where the maximum angle is opened. At this time, the door 22 is silently stopped without tilting vibration and accompanying vibration sound.

  If the gas spring 43 extends beyond the stroke end, a gas outage failure occurs. In this embodiment, the stopper member 50 stops the expansion operation of the gas spring 43 immediately before the gas spring 43 reaches the stroke end. It is possible to reliably prevent a gas outage failure of the spring 43. Therefore, the door 22 is not suddenly rotated and dropped by its own weight, and it is possible to prevent an accident that the operator is caught in the hand and to improve the safety of the centrifuge 20.

  Further, since the stopper member 50 is mounted on the gas spring 43, the stopper member 50 does not protrude as a protrusion on the outside of the housing 21, so that the appearance of the centrifuge 20 is clean, and the stopper member 50 is hand-held when being carried. There is no contact with clothes.

  In addition, when the door member 22 is opened, the stopper member 50 gradually contacts the lower surface of the upper surface plate 31 to increase the contact area S. Therefore, deformation and deterioration can be reduced, and a general inexpensive rubber such as chloroprene rubber can be used. it can.

  Furthermore, since it is only necessary to fit the stopper member 50 to the gas spring 43, no adhesive is required, and the assembly work of the stopper member 50 to the gas spring 43 is simple and easy.

It is sectional drawing of the state which opened the door of the centrifuge provided with the door mechanism which concerns on this invention. It is a side view which fractures | ruptures and shows a part of the state which closed the door of the centrifuge. It is a top view of the housing | casing of the centrifuge. It is a side view which shows the state which the gas spring extended. (A)-(c) is a figure which shows the contact area with the upper surface board of a stopper member. It is a sectional side view of the principal part of the state which opened the door of the conventional centrifuge. It is a sectional side view of the principal part of the state which closed the door of the centrifuge.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Centrifuge, 21 ... Housing, 22 ... Door, 23 ... Chamber, 24 ... Centrifuge rotor, 25 ... Drive motor, 26 ... Door mechanism, 31 ... Top plate, 33 ... Stay hole, 42 ... Hinge, 43 ... gas spring, 50 ... stopper member.

Claims (2)

A housing that opens upward, a chamber that houses a rotor that centrifuges the sample, a top plate that is attached to the top opening of the housing and covers the outer periphery of the chamber, and the housing In a centrifuge provided with a door that can be freely opened and closed via a hinge on the upper rear edge of the body and covers the upper surface opening of the housing,
A gas spring disposed in the housing and opening the door vertically upward during an extension operation; and a stopper member made of an elastic material attached to the gas spring;
The upper plate is provided with a stay hole through which the gas spring passes,
The gas spring includes a cylinder main body filled with compressed gas and a piston rod protruding from the cylinder main body, and maintains a state inclined rearward in both an extended state and a shortened state, and the cylinder is extended during an extension operation. The main body protrudes above the housing through the stay hole,
The stopper member is formed in a cylindrical body and is fitted in a loosely fitted state on the outer periphery of the cylinder body and a lower end is positioned with respect to the cylinder body. The centrifuge is characterized in that the contact area with the upper surface plate is increased by being gradually pressed against the peripheral edge of the stay hole on the lower surface of the stay, and the extension operation of the gas spring is stopped immediately before the stroke end. Door mechanism. The door mechanism of the centrifuge according to claim 1, wherein the structure for positioning the lower end of the stopper member with respect to the cylinder body includes a retaining ring fitted in an annular groove formed on an outer peripheral surface of the cylinder body, With a structure having a support washer stacked on a retaining ring,
The centrifuge door structure , wherein the stopper member is placed on the retaining ring via the support washer .

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