JP3446971B2 - Bed for X-ray CT system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray CT apparatus having a link mechanism for connecting an upper frame supporting a top plate and a lower base and moving the upper frame up and down. It is about a bed. 2. Description of the Related Art In a bed of this kind, the upper frame is deformed and bent in proportion to the load applied to the bed, that is, the weight of the subject lying on the tabletop, and the height accuracy is reduced. I do. Therefore, the above-described bending must be suppressed. Conventionally, the above-described bending has been suppressed by increasing the rigidity of the upper frame itself to increase the rigidity. [0003] As described above, in the prior art, since the flexure is suppressed by increasing the rigidity of the upper frame itself, there is a problem that the weight of the upper frame increases. An object of the present invention is to provide a bed of an X-ray CT apparatus capable of suppressing the deflection of the upper frame due to the load applied thereto without increasing the weight, and improving the height accuracy and reducing the weight. An object of the present invention is to provide a bed for an X-ray CT apparatus having a link mechanism for connecting an upper frame supporting a top plate and a lower base and moving the upper frame up and down. This is achieved by configuring at least one of the components of the link mechanism with a telescoping member that expands or contracts in a direction to reduce deflection of the upper frame due to a load. The telescopic member constituting the link mechanism is
The upper frame expands or contracts in a direction to reduce the bending due to the load applied (the direction opposite to the bending), and corrects and suppresses the bending of the upper frame. According to this, it is possible to suppress the bending of the upper frame due to the load applied thereto without increasing the rigidity of the upper frame, that is, without increasing the weight of the upper frame, thereby achieving both improvement in height accuracy and weight reduction. . An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of the bed of the X-ray CT apparatus according to the present invention. 1 is an upper frame, 2 is a lower base. A to F are fulcrums of link mechanisms for moving the upper frame 1 up and down, and rotatably support the links 3 to 6. In this case, the link 4 is formed of a hydraulic cylinder which is a telescopic member, and both ends thereof are rotatably supported by fulcrums E and F. Here, fulcrum AE length = fulcrum B
The length between F, the length between fulcrums AB = the length between fulcrums EF, and the length between fulcrums AC = the length between fulcrums CB = the length between fulcrums CD. Reference numerals 7 and 8 denote rollers which are guided by rails 9 attached to the lower base 2 and support the fulcrums B and F so as to be horizontally movable. A roller 17 is also guided by the rail 10 attached to the lower base 2 and supports the fulcrum D so as to be able to move horizontally. Reference numeral 11 denotes a hydraulic cylinder for moving the fulcrum B in the horizontal direction. Reference numeral 12 denotes a hydraulic cylinder, which moves the fulcrum D in the horizontal direction. If the hydraulic cylinder 11 expands and contracts,
The fulcrums A and E move vertically up and down, and when the hydraulic cylinder 12 expands and contracts, the fulcrums A and E move up and down in an arc. A wire rope 13 has one end fixed to the lower base 2 and the other end wound around a wire rope winding drum 14 on the upper frame 1 side. A potentiometer 20 is attached to the shaft of the drum 14 and detects the distance between the upper frame 1 and the lower base 2 (the height of the upper frame 1). Reference numerals 15, 16, and 21 denote a wire rope, a wire rope winding drum, and a potentiometer, respectively, which have the same configurations as the wire rope 13, the wire rope winding drum 14, and the potentiometer 20, respectively. Reference numeral 18 denotes a subject, and 19 denotes a top plate supported by the upper frame 1, on which the subject 18 is placed. δ indicates the deflection of the tip of the upper frame 1. Deflection δ is subject 18
Of the top plate 19 in the front-rear direction. In the above-described configuration, when the upper frame 1 is bent by the weight of the subject 18 lying on the top 19, a difference occurs in the height of the upper frame 1 detected by the potentiometers 20 and 21 at those points. . The hydraulic cylinder 4 expands and contracts in a direction to cancel this difference, and in the illustrated example, the hydraulic cylinder 4 contracts in a direction to lift the distal end side of the upper frame 1 to reduce the bending δ of the upper frame 1. As described above, according to the present invention, the bending δ can be reduced by the expansion and contraction of the expandable member. That is, without increasing the rigidity of the upper frame, in other words, without increasing its weight, it is possible to suppress the bending of the upper frame due to the load applied thereto, thereby achieving both improvement in height accuracy and reduction in weight. effective.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an embodiment of a bed of an X-ray CT apparatus according to the present invention. [Description of Signs] 1 Upper frame 2 Lower base 3, 5, 6 Link 4 Link (hydraulic cylinder as an extendable member) A to F Support points 7, 8 Rollers 9, 10 Rails 11, 12 Hydraulic cylinders 13, 15 Wire ropes 14, 16 Wire rope winding drum 18 Subject 19 Top plate 20, 21 Potentiometer δ Flexure

Claims (1)

(57) Patent Claims 1. A connecting the top frame and a lower base for supporting the top plate, in the bed of the X-ray CT apparatus having a link mechanism for moving the upper frame, the upper frame
Has a means to measure the deflection caused by the load applied to the
And at least one of the components of the link mechanism expands and contracts to reduce the above-described bending.
A bed for an X-ray CT apparatus characterized by being made of a material .