CN2248364Y

CN2248364Y - Synthetic demonstration instrument for dynamics

Info

Publication number: CN2248364Y
Application number: CN 95224425
Authority: CN
Inventors: 张学成
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-10-13
Filing date: 1995-10-13
Publication date: 1997-02-26
Anticipated expiration: 2005-10-13

Abstract

The utility model relates to a synthetic demonstration instrument for force, which is composed of a spring (4), a guide bar (1) which passes through the spring, a spring bracket (2), an equivalent ring (6) of force, a vernier (5) and two pulleys (8) (9) under the guide bar (1), wherein, the equivalent ring (6) of force is fixed with the guide bar; the vernier (5) is connected with one side of a winding wire (10) wound between the two pulleys, and the other side of the winding wire (10) is fixed with a zero adjusting screw (3) on the spring bracket which is fastened with one end of the spring. When the equivalent ring of force is tensioned by two spring scales (7) which indicate the diagram of force, the spring scale can show the diagram of two component forces, and the vernier (5) can show the diagram of the resultant force. When the component forces are altered, the resultant force is also altered, so a parallelogram can be seen evidently. The utility model has the advantages of simple structure, convenient manipulation and the demonstration of the composition of forces in the dynamic state.

Description

The composition demonstrating instrument of power

The utility model relates to a kind of composition demonstrating instrument of power, is a kind of physics teaching in secondary school instrument.

Synthetic about power on the physics lesson of middle school, be exactly the most intuitively firmly synthesis tester demonstrate.What the composition demonstrating instrument of existing power was more common has two kinds: the one, and used experiment instrument on the textbook of existing middle school can only be demonstrated two component and be 90 situations when spending; Another kind of newer experiment instrument must be pulled out earlier and be made a concerted effort, and marks with arrow then, again with also marking with arrow after two power actings in conjunction, can not demonstrate dynamically with joint efforts and the relation between the component, finish step by step, therefore relatively requires great effort.

The purpose of this utility model is at above-mentioned shortcoming, designs a kind ofly can demonstrate various angles, arbitrarily two power of size and the demonstrator of their the parallelogram of forces rule that will defer to joint efforts intuitively, dynamically.

Scheme of the present utility model is as follows: the demonstrator main body select for use a coefficient of stiffiness and the coefficient of stiffiness identical springs of standby two spring balances, this spring one end is fixed on the spring(-supported) mount.The iron stand support of spring(-supported) mount and demonstrator is connected, and brandreth props up platform and is used to hold up demonstrator, is convenient to student viewing.The other end of spring and the central authorities of passing a guide rod in it are fixed, and bearing also is connected with the equivalence ring of a power.The two ends of guide rod respectively are equipped with between the pulley and are wound with coiling.One side of guide rod---be that the spring outside has a vernier that rides on the guide rod, vernier is by wire-wound is on pulley on one side, and the another side of coiling is fixed on the spring(-supported) mount with the zeroing screw.When being used in a masterpiece on the equivalence ring, the spring elongate guide bar is along with moving, and vernier moves on guide rod, and how many springs extends, and how many verniers guide rod moves what just move, and shown in the vernier, has represented the diagram of power.When with standby two in order to the diagram spring balance of representing power during with two arbitrarily angled equivalence rings that remove pulling force, two represented scales of spring balance are the diagram of two component, vernier on the main body guide rod has been represented the diagram of a power identical with they acting in conjunction effects, the diagram of promptly making a concerted effort.

The utility model is simple in structure, but the composition demonstrating effect of power is fairly obvious.When a masterpiece time spent, vernier is exactly the diagram of this power, and when going acting in conjunction with two power at an angle to each other, vernier is exactly and the making a concerted effort of their equivalences.When changing component size direction, size, the direction of making a concerted effort also change, always but a parallelogram, can be dynamically with the size of power, the change of direction, can dynamically demonstrate at any time make a concerted effort, the size of component, direction.Intuitively, clearly, the student can sum up the parallelogram of forces rule at an easy rate, and is easy to operate.

Below in conjunction with accompanying drawing the utility model is illustrated:

Fig. 1, Fig. 2 are structural drawing of the present utility model, and Fig. 1 is the demonstrator main structure chart, Fig. 2 for go to act on two spring balances demonstration power with joint efforts with component the time condition diagram.

On main body of the present utility model, the coefficient of stiffiness of the coefficient of stiffiness of spring (4) and used two spring balances (Fig. 2 7) is identical.One end of spring (4) and spring(-supported) mount (2) are fixing, and can be fixed on the iron stand support by spring(-supported) mount (2).Guide rod (1) passes spring (4), and the other end of spring (4) is fixed on the central authorities of guide rod (1), and fixed point is connected with the equivalence ring (6) of a power, guarantee stressed do the time spent by the ring heart.The two ends of guide rod (1) respectively are fixed with a pulley (8), (9).Guide rod (1) is located outside spring---and the equivalence ring (6) of power has been ridden a vernier (5) to the end.Pulley (8), (9) are walked around in coiling (10), on one side coiling (10) and above-mentioned vernier (5) fixing, the coiling of another side is fixed on the spring(-supported) mount (2) with the screw (3) that returns to zero.

When being used in equivalence ring (6) with a masterpiece, spring (4) elongation.Guide rod (1) moves thereupon, and the diagram of this power is just expressed in the displacement of the vernier (5) on the guide rod (1).

When two spare spring scales (7) as shown in Figure 2 remove the equivalence ring (6) of pulling force, the diagram of two component F1, F2 is promptly represented in the scale indication of two spare spring scales (7), and the scale on the vernier (5) has promptly been represented the diagram of making a concerted effort identical with they acting in conjunction effects.Change component F1, F2, make a concerted effort, but total energy is formed a parallelogram also along with change.

The utility model demonstration is convenient, the vector end coupled together with tangible line, and be the adjacent side and the diagonal line of a parallelogram as can be seen, component changes, and makes a concerted effort also to change, and makes the student can sum up the parallelogram rule of exerting oneself at an easy rate.

Claims

1, the composition demonstrating instrument of power, comprise two standby spring balances (7), it is characterized in that the identical spring (4) of the coefficient of stiffiness that the main body of above-mentioned demonstrator has a coefficient of stiffiness and above-mentioned two spare springs to claim, there is a guide rod (1) to pass from spring (4), one end of above-mentioned spring (4) and spring suppport (2) are fixing, the central authorities of the other end of spring (4) and guide rod (1) fixedly connected, fixed point is connected to the equivalence ring (6) of a power, a pulley (8) respectively is equipped with at the two ends of guide rod (1), (9) be wound with coiling (10) between, vernier (5) ride over being positioned at outside the spring (4) of guide rod (1) to the guide rod end and and be around in two pulleys (8), (9) one side of the coiling between (10), the another side of coiling (10) is fixed on the spring(-supported) mount (2) by zeroing screw (3).