CN2144299Y - Portable high-precision spring balance - Google Patents

Abstract

The utility model relates to a portable high-precision spring balance, whose load weight is transmitted to two weight-measuring springs through a balancing stand. The two weight-measuring springs are made to generate deformation, and drive a driving mechanism composed of a rack gear, a duplicate gear, a kilogram gear and a gram gear; the load weight is displayed through a pointer. Because the closed loop extension spiral spring is adopted to be used as the measuring spring of the spring balances and the two shaft holes which support the duplicate gear are long holes, the portable high-precision spring balance does not need to be adjusted to zeroing before being used; the defect that the pointer of the existing dial type spring balances is unable to appoint to the zero position when in still standing state is eliminated; the static gap and the dynamic gap among the components of the driving mechanism are made to be smaller; consequently the weighing precision and the sensitivity of the portable high-precision spring balance are enhanced.

Description

Portable high-precision spring balance

It is the weighing apparatus of feature with the element that is applied to produce elastic deformation that the utility model relates to a kind of.

Normally used dial-type spring balance all is to utilize Hooke's law to be principle of work, make the load weight on the hook of weighing pass to two weight sensing springs by the balancing stand that hang to connect with it, two weight sensing springs deform under the effect of load, the gear train that constitutes by tooth bar and gear passes to pointer to deflection, thereby makes pointer indicate the weight readings of load on scale.Because the weight effect of spring balance self, so pointer can not be specified zero-bit under static condition, must rest on the scale division value away from zero-bit, could make like this when critical excitation is mentioned spring balance, the pointer displacement amount that own wt produced of spring balance is cancelled out each other with the pointer displacement amount that departs from, make the pointer indication in zero-bit, but the accuracy of this type of scale nulling is not high, often need by regulating null setting, just can make pointer adjustment zero-bit, so comparatively bother when using, and effect is also undesirable, if make pointer away from zero-bit, main parts size (as: the weight sensing spring of spring balance, balancing stand, tooth bar, gears etc.) extension connects each other, engagement just must be quite loose, static clearance between them and dynamic clearance are quite big, thereby make weighing precision and sensitivity lower, and the minimum division value of its scale is more than 20 grams.

The purpose of this utility model is to provide a kind of weighing precision and sensitivity portable high-accuracy spring balance higher, easy to use.

For achieving the above object, the utility model select for use two have certain initial tension close the circle draft helical spring as the weight sensing spring of spring balance, bear for two weight sensing springs as the tensile load mean allocation own wt of spring balance, the drawing stress that the own wt of spring balance is produced is corresponding with the initial stress of two weight sensing springs also equal, the initial tension that is to say spring balance own wt and two weight sensing springs is in equilibrium state, spring balance pointer when static state specifies in zero-bit, in case add when weighing load, equilibrium state will be broken, two weight sensing springs will deform, its deflection passes to pointer by the gear train of the company's of extension engagement with it, pointer just begins to move from zero-bit, thereby indicates the weight readings of plus load.In the gear train, be connected the tooth bar on the balancing stand and the pinion of duplicate gear, the pinion wheel of duplicate gear again with the kilogram gearing mesh that kilogram pointer is installed, the gear wheel of duplicate gear and the gram gearing mesh that the gram pointer is installed, and the axis hole of supporting double crosslinking gear shaft is an elongated hole, the axis hole long axis becomes 0～40 ° of angle with horizontal line, so that duplicate gear can be done the directed displacement of distance element, be connected with a little extension spring between tooth bar and the balancing stand, so that being close to the pinion wheel and the duplicate gear of duplicate gear, tooth bar is close to gram gear and kilogram gear, thereby do not influencing under the prerequisite that is meshing with each other between them and runs well, static state between them and dynamic clearance are reduced to bottom line, improve the weighing precision and the sensitivity of spring balance greatly.

In conjunction with the accompanying drawings the utility model is elaborated below by embodiment:

Fig. 1 is the utility model front view.

Fig. 2 is the utility model backsight inner structure synoptic diagram.

Suspension hook in the utility model (5) is hung the bottom that is connected in T frame balancing stand (6), two weight sensing springs (8), (1) two ends hang respectively and are connected in the extension spring support (14) that is fixed on housing (13) top and the two ends of balancing stand, tooth bar (10) is movably riveted on the balancing stand (6), housing (13) panel back has a projection, central shaft location-plate (3) is fixed on the projection, and kilogram gear (12) and gram gear (11) are sleeved on the central shaft (4) on the central shaft location-plate, duplicate gear (9) by axle be bearing in its corresponding housing (13) panel on axis hole and the axis hole (2) on the central shaft location-plate on, this axis hole is an elongated hole, the elongated hole long axis becomes 30 ° of angles with horizontal line, and make the pinion of tooth bar (10) and duplicate gear (9), duplicate gear (9) big, pinion wheel respectively with the gram gear (11), kilogram gear (12) engagement, gram gear (11), the kilogram gear (12) the center barrel on be separately installed with the gram pointer (17) with the kilogram the little extension spring of pointer (18) (7) extension be connected between T type balancing stand (6) and the tooth bar (10) weight sensing spring (1), (8) all adopt have certain initial tension close the circle draft helical spring.

When this portable high-accuracy spring balance is weighed, the weight that suspension hook (5) is gone up load passes to weight sensing spring (8) through T type balancing stand (6), (1), weight sensing spring (8), (1) distortion that is stretched is done to move straight down, drive tooth bar (10) displacement in the same way synchronously, because the pinion of tooth bar (10) and duplicate gear (9), the displacement of tooth bar (10) just drives duplicate gear (9) rotation like this, duplicate gear (9) rotates and has just driven kilogram gear (12) and gram gear (11) rotation respectively, thereby drive kilogram pointer (18), gram pointer (17) indicates the weight that suspension hook (5) is gone up load on scale (19), kilogram gear (12) is 1:5 with the rotation ratio of gram gear (11) here.This scale if the nulling accuracy of pointer is on the low side to some extent, can be adjusted by the pointer null setting of being made up of fine-tuning nut (16), pressure little spring (15) extension spring support (14) etc. after use a period of time.

The utility model also can be installed on the generic container, in order to the weight of metering liquid, solid, opaque and particulate material.

What the utility model weight sensing spring owing to adopt had certain initial tension closes the circle draft helical spring, so, when promptly having eliminated existing dial-type spring balance static condition, pointer can not be specified the defective of zero-bit, saved the program that must return to zero earlier before weighing is used, overcome the excessive defect of dynamic clearance in the gear train again, thereby improved weighing precision and sensitivity.Again because two axis holes of supporting duplicate gear are elongated hole, duplicate gear can be done to be connected with a little extension spring between the directed displacement of distance element and tooth bar and the balancing stand in this elongated hole, so, make static clearance and dynamic clearance between the gear train parts be reduced to bottom line, thereby the weighing precision and the sensitivity of this scale have further been improved, under the situation of 5 kilograms of weight of maximum capacity, minimum calibration reaches 5 grams.

Claims (3)

1, a kind of portable high-accuracy spring balance, suspension hook (5) is hung the bottom that is connected in T type balancing stand (6), two weight sensing springs (8), (1) two ends hang respectively and are connected in the extension spring support (14) that is fixed on housing (13) top and the two ends of T type balancing stand (6), tooth bar (10) is movably riveted on the balancing stand (6), the pinion that it is characterized in that tooth bar (10) and duplicate gear (9), the pinion wheel of duplicate gear (9) meshes with the kilogram gear (12) that a kilogram pointer (18) is installed again, the gear wheel of duplicate gear (9) and gram gear (11) engagement that gram pointer (17) is installed, and the axis hole of supporting double crosslinking gear shaft is an elongated hole, is connected with a little extension spring (7) between tooth bar (10) and the balancing stand (6).

2, portable high-accuracy spring balance according to claim 1, it is characterized in that weight sensing spring (1), (8) be have certain initial tension close the circle draft helical spring.

3, portable high-accuracy spring balance according to claim 1, the long axis that it is characterized in that supporting the microscler axis hole of double crosslinking gear shaft becomes 0～40 ° of angle with horizontal line.

Images